Protein transduction domains mimics

ABSTRACT

The invention generally relates to synthetic mimics of cell penetrating peptides. More particularly, the invention relates to certain novel monomers, oligomers and polymers (e.g., co-polymers) that are useful for the preparation of synthetic mimics of cell penetrating peptides, their compositions, preparations and use.

PRIORITY CLAIMS AND RELATED APPLICATIONS

This application claims the benefit of priority to and is a continuationof U.S. Ser. No. 13/703,645, with the filing date of Jun. 26, 2013,which is the U.S. National Phase application of and claims priority tointernational application PCT/US2011/041906, filed Jun. 24, 2011, whichclaims the benefit of priority from U.S. Provisional Application Ser.No. 61/358,533, filed on Jun. 25, 2010, the entire content of each ofwhich is incorporated herein by reference in its entirety.

TECHNICAL FIELD OF THE INVENTION

The invention generally relates to synthetic mimics of proteintransduction domains. More particularly, the invention relates tocertain novel monomers, oligomers and polymers (including co-polymers)that are useful for the preparation of synthetic mimics of proteintransduction domains, related compositions and methods of preparationand use.

BACKGROUND OF THE INVENTION

Protein transduction domains (PTDs), also known as cell penetratingpeptides (CPPs), are oligo- or poly-cationic peptides that canfacilitate cellular uptake of many different cargos such as smallmolecules, proteins, DNA/RNA and nanoparticles.

In 1988, Frankel and Pabo, and Green and Lowestein independentlyreported that TAT protein from HIV is able to cross cellular membranesand localize inside cells. (Frankel, et al. 1988 Cell 55, 1189-1193;Green, et al. 1988 Cell 55, 1179-1188.) Since then, protein transductiondomains have been under intense study for two major reasons. First, itis well known that the plasma membrane limits the transport of highlycharged molecules. The fact that PTDs, with multiple cationic centers,readily transverse the membrane is important for a fundamentalunderstanding of membrane transport. Second, the ability of PTDs todeliver cargo (proteins, antibodies, and nucleic acids) into mammaliancells offers possibilities for both new therapies and new tools to studycell biology. (Fonseca, et al. 2009 Adv. Drug. Deliv. Rev. 61, 953-964;Gump, et al. 2007 TRENDS Mol Med 13, 443-448; Sebbage, 2009 BioscienceHorizons 2, 64-72.)

PTDs primarily consist of cationic amino acid sequences such asarginines and/or lysines. Early studies showed that the translocationabilities of PTDs were directly associated with the presence of arginineresidues. (Schwarze, et al. 2000 Trends Pharmacol Sci 21, 45-48; Futaki,et al. 2003 J. Mol. Recog. 16, 260-264; Fischer, et al. 2000 J. PeptideRes. 55, 163-172; Mitchell, et al. 2000 J. Peptide Res. 56, 318-325;Futaki, et al. 2001 J. Biol. Chem. 276, 5836-5840; Wender, et al. 2000Proc. Natl. Acad. Sci. USA 97, 13003-13008.) For example, in the case ofTAT₄₉₋₅₇ (RKKRRQRRR), replacement of the arginine amino acids withalanine or other cationic residues (lysine, histidine, and orthonine),led to reduced cellular uptake. In contrast, substitution of allnon-arginine residues with arginine (i.e. Arg-replacement) resulted inenhanced internalization efficiency (e.g., R9 was reported to be 20-foldmore efficient than TAT₄₉₋₅₇). In addition to arginine content, thepeptide length sets another parameter for cellular uptake. It wasreported that there is an optimum length for maximum activity.(Rothbard, et al. 2002 J. Med. Chem. 45, 3612-3618.)

Although the number of known PTDs has increased significantly and smallmolecule synthetic analogues have been attempted, design and synthesisof simple structures that capture the biological activity of peptides,proteins, and oligonucleotides remains an important challenge. (e.g.,Lienkamp, et al. 2008 J A. Chem. Soc. 130, 9836-9843; Gabriel, et al.2008 Biomacromolecules 9, 2980-2983.) There is a significant unmet needfor novel approaches, compositions and methods that provide syntheticmimics of PTDs having improved cell-penetrating properties.

SUMMARY OF THE INVENTION

The invention is based in part on the discovery of that, unlike certainknown PTDs, such as heptaarginine and polyarginine that requirecounterion for activation, a number of guanidinium-containing polymersand block copolymers are self-activating in anion transport across lipidbilayers. The invention provides novel monomers, oligomers and polymers(e.g., co-polymers) that are useful for the preparation of syntheticmimics of cell penetrating peptides. The invention additionally providesrelated-compositions and methods of preparations and use of the novelmonomers, oligomers and polymers disclosed herein.

In one aspect, the invention generally relates to a block co-polymerhaving the Formula of (I):

wherein

-   -   X₁, X₂ each is independently O, CH₂ or substituted CH₂;    -   Y₁₁, Y₁₂ each is independently a single bond or a linking group;    -   Z₁₁, Z₁₂ each is independently hydrogen, or an —N(R_(z))₂,        alkyl, substituted alkyl, aryl, substituted aryl group, with the        proviso that at least one of Z₁₁ and Z₁₂ comprises N(R_(z))₂ or

-   -   Y₂₁, Y₂₂ each is independently a single bond or a linking group;    -   Z₂₁, Z₂₂ each is independently hydrogen, or an —OR_(z), alkyl,        substituted alkyl, aryl, substituted aryl group;    -   R_(z) each is independently hydrogen, or an alkyl, substituted        alkyl, aryl, substituted aryl, poly(ethylene oxide) group;    -   R is hydrogen, a C₁-C₆ alkyl or a poly(ethylene oxide) group;        and    -   m, n each is independently an integer from about 2 to about 300.

In another aspect, the invention generally relates to a composition thatincludes: a polymer having a structural unit of Formula (II):

-   -   wherein    -   X₁ is independently O, CH₂ or substituted CH₂;    -   Y₁₁, Y₁₂ each is independently a single bond or a linking group;    -   Z₁₁, Z₁₂ each is independently hydrogen, or an —N(R_(z))₂,        alkyl, substituted alkyl, aryl, substituted aryl group, with the        proviso that at least one of Z₁₁ and Z₁₂ comprises —N(R_(z))₂ or

-   -   R_(z) each is independently hydrogen, or an alkyl, substituted        alkyl, aryl, substituted aryl, poly(ethylene oxide) group;    -   R is hydrogen, a C₁-C₆ alkyl group or a poly(ethylene oxide)        group; and    -   n is independently an integer from about 2 to about 300; and        a therapeutic agent having a biological effect under        physiological conditions.

In yet another aspect, the invention generally relates to a compositionthat includes: a polymer having a structural unit of Formula (II):

-   -   wherein    -   X₁ is independently O, CH₂ or substituted CH₂;    -   Y₁₁, Y₁₂ each is independently a single bond or a linking group;    -   Z₁₁, Z₁₂ each is independently hydrogen, or an —N(R_(z))₂,        alkyl, substituted alkyl, aryl, substituted aryl group, with the        proviso that a least one of Z₁₁ and Z₁₂ comprises —N(R_(z))₂ or

-   -   R_(z) each is independently hydrogen, or an alkyl, substituted        alkyl, aryl, substituted aryl, poly(ethylene oxide) group;    -   R is hydrogen, a C₁-C₆ alkyl group or a poly(ethylene oxide)        group; and    -   n is independently an integer from about 2 to about 300; and        a diagnostic agent capable of emitting a detectable signal

In yet another aspect, the invention generally relates to a blockco-polymer having the Formula of (III):

-   -   wherein    -   X₁, X₂ each is independently O, CH₂ or substituted CH₂;    -   Y₁ is a linking group;    -   Z₁ is comprises —N(R_(z))₂ or

-   -   Y₂ is a single bond or a linking group;    -   Z₂ is hydrogen, or an alkyl or substituted alkyl group;    -   R_(z) is hydrogen, or an alkyl, substituted alkyl, aryl,        substituted aryl group;    -   R is hydrogen, a C₁-C₁₂ alkyl group or a poly(ethylene oxide)        group; and    -   m, n each is independently an integer from about 2 to about 300.

In yet another aspect, the invention generally relates to a blockcopolymer that includes a structural unit of the formula:

wherein X is an anion.

In yet another aspect, the invention generally relates to a compositionthat includes: a polymer having a structural unit of Formula (IV):

-   -   wherein    -   X₁ is O, CH₂ or substituted CH₂;    -   Y₁ is a linking group;    -   Z₁ is comprises —N(R_(z))₂ or

-   -   R_(z) is hydrogen, or an alkyl, substituted alkyl, aryl,        substituted aryl group;    -   R is hydrogen, a C₁-C₁₂ alkyl group or a poly(ethylene oxide)        group; and    -   n is independently an integer from about 2 to about 300.        a therapeutic agent having a biological effect under        physiological conditions.

In yet another aspect, the invention generally relates to a compositionthat includes: a polymer having a monomer of Formula (IV):

-   -   wherein    -   X₁ is O, CH₂ or substituted CH₂;    -   Y₁ is a linking group;    -   Z₁ is comprises —N(R_(z))₂ or

-   -   R_(z) is hydrogen, or an alkyl, substituted alkyl, aryl,        substituted aryl group;    -   R is hydrogen, a C₁-C₁₂ alkyl group or a poly(ethylene oxide)        group; and    -   n is independently an integer from about 2 to about 300.        a diagnostic agent capable of emitting a detectable signal

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Structures of Methyl-(Mn) and Di-(Dn) guanidinium polymers.

FIG. 2: Internalization of molecules in HEK293T cells. a) RepresentativeFACS histogram showing the cellular uptake of 5 μM NBD-labeled D9molecule at 37° C. after treatment with the NBD/dithionite assay. Thesolid gray curve is untreated HEK293T cells; the red line representscells treated with D9. b) HEK293T cells were treated with di-guanidiniumpolymers (D5, D9, D12, D18) at 37° C. The amount of surface bound andinternalized molecules was determined by the NBD/dithionite assay. Theamount of molecules bound to the surface (open bars) was obtained bysubtracting the amount of internalized PTDMs (closed bars) from thetotal mean fluorescence intensity. The mean fluorescence of internalizedpolymers (after quenching the cell surface bound fraction of polymers bydithionite) was divided by the total mean fluorescence (beforedithionite quenching) and multiplied by 100 to obtain the percentcellular uptake. *(P<0.05) of D5 versus R9 mean fluorescence at 37° C.Translocation of polymers were represented as the percentage ofinternalization in HEK293T cells treated with 5 μM NBD-labelednonaarginine (R9) control and methyl-guanidinium polymers (Mn) c) at 4°C. and d) at 37° C. **(P<0.01) of M9 versus R9 percent cellular uptake.e) Percent cellular uptake in HEK293T cells treated with 5 μMNBD-labeled di-guanidinium polymers (Dn) at 4° C., *(P<0.05) of D9versus D18 percent cellular uptake and f) at 37° C., **(P<0.01) of D9versus D18 percent cellular uptake. Each point is the mean±S.D. of threeseparate determinations.

FIG. 3: Percent cellular uptake of NBD-labeled polymers in (a and b) CHOand (c and d) Jurkat T cells at 37° C. and 4° C. CHO cells wereincubated with 5 μM NBD-labeled polymers a) at 37° C., *(P<0.05) of D5versus M9 percent cellular uptake, and b) at 4° C., **(P<0.01) of D5versus M9 percent cellular uptake. Jurkat T cells were treated with 2.5μM NBD-labeled polymers c) at 37° C., **(P<0.01) of M9 versus D5 percentcellular uptake, and d) at 4° C. For the calculation of %internalization, experiments were done with dithionite quenched andwithout dithionite treated cells and the percent ratio ofinternalization represents the transduction efficiency of the molecules.Each point is the mean±S.D. of three separate determinations.

FIG. 4: Localization of D9 polymers in CHO cells. CHO cells wereincubated with 5 μM NBD-labeled D9 polymer for 60 min at 37° C., afterthe last washing step cells were subsequently incubated with Lysotrackerred-99 for 4 min, washed, and placed in ice-cold HBSS buffer. a)Localization of D9 molecules (green channel) b) localization ofLysotracker red-99 (red channel), and c) colocalization of D9 moleculesand lysotracker (overlay). Note that all cells have a uniform greenbackground demonstrating D9 is present outside of lysosome/endosomes.

FIG. 5: Comparison of the percent cellular uptake of NBD-labeled M9, D5and D9 in HEK293T, CHO and Jurkat T cells at (a) 4° C. and (b) 37° C.HEK293T and CHO cells were incubated with 5 μM NBD-labeled polymers, andJurkat T cells were incubated with 2.5 μM NBD-labeled polymers. For thecalculation of % internalization, experiments were done with dithionitequenched and without dithionite treated cells and the percent ratio ofinternalization represents the transduction efficiency of the molecules.Each point is the mean±S.D. of three separate determinations.

FIG. 6: Synthesis of monomers.

FIG. 7: ¹H NMR of Compound 3a, CDCl₃.

FIG. 8: ¹³C NMR of Compound 3a, CDCl₃.

FIG. 9: ¹H NMR of Compound 3b, CDCl₃.

FIG. 10: ¹³C NMR of Compound 3b, CDCl₃.

FIG. 11: Synthesis of NBD-labeled Compound 4.

FIG. 12: ¹H NMR of NBD-labeled compound 4, DMSO-d6.

FIG. 13: Synthesis of NBD-labeled polymers.

FIG. 14: GPC-UV trace of NBD-labeled polymer 6a.

FIG. 15: ¹H NMR of Polymer 5a, DMSO-d6.

FIG. 16: ¹H NMR of Polymer 5b, DMSO-d6.

FIG. 17: ¹H NMR of Polymer 6a, DMSO-d6.

FIG. 18: ¹H NMR of Polymer 6b, DMSO-d6.

FIG. 19: ¹H NMR of Polymer 7a, DMSO-d6.

FIG. 20: ¹H NMR of Polymer 7b, DMSO-d6.

FIG. 21: Synthesis of NBD-labeled polymer 8.

FIG. 22: ¹H NMR of Polymer 8, DMSO-d6.

FIG. 23: Schematic representation of PTDM internalization. K₁ is theconstant for the equilibrium between PTDM in solution and on cellsurface, and K₂ is the equilibrium coefficient for cell surface bindingand internalization processes. Especially, K₂ is specific for eachmolecule, and determines the internalization efficiency for each PTDM.

FIG. 24: Cellular uptake of NBD-labeled polymers at 37° C. in HEK293Tcells. HEK293T cells were incubated with 5 μM NBD-labeled polymers incomplete growth medium with 10% serum, then washed and resuspended inCBE buffer for FACS analysis and as a last step treated withNBD-dithionite quenching assay. Bars labeled as internalized representmean fluorescence after dithionite treatment and total stands for meanfluorescence before dithionite treatment. Each point is the mean±S.D. ofthree separate determinations.

FIG. 25: Cellular uptake of NBD-labeled polymers at 4° C. in HEK293Tcells. HEK293T cells were incubated with 5 μM NBD-labeled polymers incomplete growth media with 10% serum, then washed and resuspended in CBEbuffer for FACS analysis and as a last step treated with NBD-dithionitequenching assay. Bars labeled as internalized represent meanfluorescence after dithionite treatment and total stands for meanfluorescence before dithionite treatment. Each point is the mean±S.D. ofthree separate determinations.

FIG. 26: Cellular Uptake of NBD-labeled polymers at 37° C. in Jurkat Tcells. Jurkat T cells were incubated with 2.5 μM NBD-labeled polymers incomplete growth media with 10% serum, then washed and resuspended in CBEbuffer for FACS analysis and as a last step treated with NBD-dithionitequenching assay. Bars labeled as internalized represent meanfluorescence after dithionite treatment and total stands for meanfluorescence before dithionite treatment. Each point is the mean±S.D. ofthree separate determinations.

FIG. 27: Cellular Uptake of NBD labeled polymers at 4° C. in Jurkat Tcells. Jurkat T cells were incubated with 2.5 μM NBD-labeled polymers incomplete growth media with 10% serum, then washed and resuspended in CBEbuffer for FACS analysis and as a last step treated with NBD-dithionitequenching assay. Bars labeled as internalized represent meanfluorescence after dithionite treatment and total stands for meanfluorescence before dithionite treatment. Each point is the mean±S.D. ofthree separate determinations.

FIG. 28: Cellular Uptake of NBD-labeled polymers at 37° C. in CHO cells.CHO cells were incubated with 5 μM NBD-labeled polymers in completemedia with 10% serum, then washed and resuspended in CBE buffer for FACSanalysis and as a last step treated with NBD-dithionite quenching assay.Bars labeled as internalized represent mean fluorescence afterdithionite treatment and total stands for mean fluorescence beforedithionite treatment. Each point is the mean±S.D. of three separatedeterminations.

FIG. 29: Cellular Uptake of NBD-labeled polymers at 4° C. in CHO cells.CHO cells were incubated with 5 μM NBD-labeled polymers in completegrowth media with 10% serum, then washed and resuspended in CBE bufferfor FACS analysis and as a last step treated with NBD-dithionitequenching assay. Bars labeled as internalized represent meanfluorescence after dithionite treatment and total stands for meanfluorescence before dithionite treatment. Each point is the mean±S.D. ofthree separate determinations.

FIG. 30: Percent cellular uptake vs toxicity HEK293T cells. Mn(triangles) and Dn (squares) polymers were plotted % cellular uptakeagainst toxicity of polymers at both a) 37° C. and b) 4° C. Theconcentrations for toxicity of polymers were reported as lethalconcentrations (LC₅₀) at which half members of the tested population ofcells were detected as damaged and/or dead. Each plot was divided intofour quadrants to specify molecules' efficiency as a function of percentcellular uptake and toxicity, quandrants II and upper parts of Irepresent the most efficient molecules with high cellular uptake and lowtoxicity. Each point is the mean±S.D. of three separate determinations.

FIG. 31: Cytotoxicity in Jurkat T cells. 7-AAD viability assay was usedto determine the cytotoxicity of the polymers.

FIG. 32: Cytotoxicity in CHO cells. 7-AAD viability assay was used todetermine the cytotoxicity of the polymers.

FIG. 33: Cellular uptake assay for negative controls. Jurkat T cellswere treated with NBD-labeled polymer 8, monomer 4 or M9 to demonstratethat NBD dye does not have an effect on the internalization ofmolecules. Neither NBD-labeled polymer 8 nor the monomer 4 were ableenter to the cells even at higher concentrations. On the other hand, M9had superior uptake efficiency at a concentration of 2.5 μM, andfurthermore its internalization efficiency was doubled at 5 μM.

FIG. 34: HEK293T cells dot plots showing NBD-positive cells.

FIG. 35: Untreated controls, CHO and Jurkat T cells. FIG. S31: CHO cellsdot plots showing NBD-positive cells.

FIG. 36: CHO cells dot plots showing NBD-positive cells.

FIG. 37: Jurkat T cells dot plots showing NBD-positive cells.

FIG. 38. Structure of oxanorbornenes derived guanidino copolymers usedin this study.

FIG. 39. Retention time (R_(t)) on a reverse-phase C8-HPLC column (underisocratic condition, 100% acetonitrile) of the corresponding hydrophobicmonomers that were copolymerized with the guanidine monomers. IndividualR_(t) (min) of the monomers: Ph, 4.15; Np, 4.27; Oc, 4.50; Cy, 4.55; Py,4.57.

FIG. 40. (A) A plot of 1/EC₅₀ (for the PTDMs copolymer) vs. 1/R_(t) (forthe corresponding monomers) for GOc, GCy, GPy, and GPh. (B)Concentration (c) dependent activity of copolymers GOc, GCy, GPh andpolyarginine (pR) in EYPC⊃CF vesicles with fit to Hill equation.

FIG. 41. Hill plot of GNp copolymers with different guanidine tonaphthyl repeat unit ratios in EYPC⊃CF vesicles with fit to Hillequation.

FIG. 42. Representative normalized original kinetics for GOc, GCy, GPh,GNp, GPy, and polyarginine (pR) following CF fractional emissionintensity I_(f) (λ_(ex)=492 nm, λ_(em)=517 nm) as a function of timeduring the addition of EYPC-LUVs⊃CF (t=0 s), polymer (t=100 s) andTriton X-100 (t=900 s).

FIG. 43. Fractional emission intensity I_(f) at 800 s from FIG. 41(transmembrane activity Y) was plotted against polymer concentration (c)and fitted to hill equation S2.

FIG. 44: siRNA delivery into Jurkat T cells. a) Chemical structure ofPTDM-1, n=9. b) Chemical structure of PTDM-2, n=m=5. c) Flow cytometryanalysis showing Jurkat T cells treated with PTDM-1 (1 μM)/FITC-siRNA(50 nM) complexes in complete media (blue curve) or serum free media(green curve) for 4 h and compared with untreated cells (red solidcurve) d) Flow cytometry analysis showing Jurkat T cells treated withPTDM-2 (1.7 μM)/FITC-siRNA (50 nM) complexes in complete media (bluecurve) or serum free media (green curve) for 4 h and compared withuntreated cells (red solid curve) e) Flow cytometry analysis showingJurkat T cells treated with PTDM-1 (1 μM)/FITC-siRNA (50 nM) complexesin serum-free media for 1 h at 4° C. (blue curve) or 37° C. (greencurve) and compared with untreated cells (red solid curve). f) Flowcytometry analysis showing Jurkat T cells treated with PTDM-2 (1.7μM)/FITC-siRNA (50 nM) complexes in serum-free media for 1 h at 4° C.(blue curve) or 37° C. (green curve) and compared with untreated cells(red solid curve) g) Flow cytometry analysis showing Jurkat T cellsstained with fluorescent PE-anti Notch 1, 72 h after treatment withsiRNA complexes; blue curve: cells treated with PTDM-1 (2 μM)/siN1 (100nM) complexes, green curve: cells treated with PTDM-2 (3.5 μM)/siN1 (100nM) complexes, red solid curve: untreated cells. h) Flow cytometryanalysis showing Jurkat T cells stained with fluorescent PE-anti Notch1, 72 h after the siRNA treatment; red curve: untreated cells, bluecurve: cells treated with PTDM-1 (1.6 μM)/siCont (80 nM) complexes,black curve: cells treated with only PTDM-1 (1.6 μM), green curve: cellstreated with PTDM-1 (1.6 μM)/siN1 (80 nM) complexes. i) Relative Notch 1expression level in Jurkat T cells 72 h after treatment with PTDM-1/siN1complexes, PTDM-1/siCont complexes, Hifect/siN1, Lipofectamine 2000/siN1and Fugene HD/siN1 as analyzed by flow cytometry. Cells were treatedwith siRNA-carrier complexes in serum free medium for 4 h, then mediumwas exchanged with fresh complete growth medium (final siRNAconcentration is 80 nM). Values and error bars represent the mean±SD ofthree independent experiments. *(P<0.01) of siN1 versus siCont deliveredby PTDM-1.

FIG. 45: Time dependent down regulation of Notch 1 by PTDM-2/siN1. a)Flow cytometry analysis showing PBMCs stained with fluorescent PE-antiNotch 1, 24 h, 48 h, 72 h or 96 h after treatment with siRNA complexes;blue curve: cells treated with PTDM-2 (3.5 μM)/siN1 (100 nM) complexes,green curve: cells treated with PTDM-2 (3.5 μM)/siCont (100 nM)complexes, red solid curve: untreated cells. b) Relative Notch 1expression levels in PBMCs 24 h, 48 h, 72 h or 96 h after treatment withPTDM-2 (3.5 μM)/siN1 (100 nM) or PTDM-2 (3.5 μM)/siCont (100 nM)complexes. c) Cell proliferation assay. Equal numbers of PBMCs wereseeded and treated with either PTDM-2 (3.5 μM)/siN1 (100 nM) or PTDM-2(3.5 μM)/siCont (100 nM) complexes. Cell proliferation was measured bycell counting with a hemacytometer at indicated time points. d) 7-AADviability test. PTDM-2 (3.5 μM)/siN1 (100 nM) or PTDM-2 (3.5 μM)/siCont(100 nM) treated cells were stained with 7-Amino-Actinomycin D (7-AAD)at indicated time points after the treatment. e-f) Relative Notch 1expression level in PBMCs from three different donors (Donor A, B and C)72 h after treatment with PTDM-2/siN1 and PTDM-2/siCont as a final siRNAconcentration of 100 nM or 150 nM. Cells were treated with PTDM/siRNAcomplexes in complete media for 4 h, and then cells were transferred toanti-CD3/CD28 coated wells. Protein level was analyzed at 72 h after thetreatment by flow cytometry. Values and error bars represent the mean±SDof three independent experiments. *(P<0.05) of siN1 versus siContdelivered by PTDM-2. **(P<0.01) of siN1 versus siCont delivered byPTDM-2.

FIG. 46: Effect of Notch 1 down regulation by siRNA on CD4⁺T celldifferentiation at 72 h. a) Percentage of Notch 1 expressing T_(H)1polarized CD4⁺T cells 72 h after treatment with PTDM-2/siN1 orPTDM-2/siCont. b) Relative Notch 1 expression in T_(H)1 polarized CD4⁺Tcells 72 h after treatment with PTDM-2/siN1 or PTDM-2/siCont. c) Flowcytometry analysis showing T_(H)1 polarized CD4⁺T cells stained withfluorescent PE-anti Notch 1 72 h after treatment with siRNA complexes;blue curve: PTDM-2/siN1 treated cells, green curve: PTDM-2/siCont, redsolid curve: untreated cells. d) Percentage of T-bet expressing T_(H)1polarized CD4⁺T cells 72 h after treatment with PTDM-2/siN1 orPTDM-2/siCont. e) Relative T-bet expression in T_(H)1 polarized CD4⁺Tcells 72 h after treatment with PTDM-2/siN1 or PTDM-2/siCont. f) Flowcytometry analysis showing T_(H)1 polarized CD4⁺T cells stained withfluorescent Alexa Fluor 647 anti-T-bet 72 h after treatment with siRNAcomplexes; blue curve: PTDM-2/siN1 treated cells, green curve:PTDM-2/siCont, red solid curve: untreated cells. g-i) Flow cytometryanalysis showing T_(H)1 polarized CD4⁺T cells stained with fluorescentAPC-anti IFN-γ 72 h after treatment with siRNA complexes; g) untreatedcells, h) PTDM-2/siCont treated cells, i) PTDM-2/siN1 treated cells. j)Percentage of IFN-γ expressing T_(H)1 polarized CD4⁺T cells 72 h aftertreatment with PTDM-2/siN1 or PTDM-2/siCont. k) Relative IFN-γexpression in T_(H)1 polarized CD4⁺T cells 72 h after treatment withPTDM-2/siN1 or PTDM-2/siCont. Values and error bars represent themean±SD of three independent experiments. *(P<0.05) of siN1 versussiCont delivered by PTDM-2. **(P<0.01) of siN1 versus siCont deliveredby PTDM-2.

FIG. 47: GPC IR-trace of 1^(st) (red curve) and 2^(nd) (black curve)blocks of Polymer 5a.

FIG. 48: Relative Notch 1 expression level in PBMCs. a) Relative Notch 1expression level in PBMCs 72 h after treatment with PTDM-1/siN1 andPTDM-1/siCont (final siRNA concentration is 60 nM). b) Relative Notch 1expression level in PBMCs 72 h after treatment with PTDM-2/siN1 andPTDM-2/siCont (Final siRNA concentration is 60 nM). c, d, e) RelativeNotch 1 expression level in PBMCs from three different donors (donor A,B, and C) 72 h after treatment with with PTDM-2/siN1 and PTDM-2/siCont(Final siRNA concentration is 60 nM). Cells were treated with PTDM/siRNAcomplexes in serum free medium for 4 h, then medium was exchanged withfresh complete growth medium, and cells were transferred toanti-CD3/CD28 coated wells for activation. Protein level was analyzed byflow cytometry 72 h after the treatment by flow cytometry. Values anderror bars represent the mean±SD of three independent experiments.*(P<0.05) of siN1 versus siCont delivered by PTDM-2. **(P<0.01) of siN1versus siCont delivered by PTDM-1 or PTDM-2.

FIG. 49: Effect of Notch 1 down regulation by siRNA on CD4⁺Tdifferentiation at 48 h. a) Percentage of Notch 1 expressing T_(H)1polarized CD4⁺T cells 48 h after treatment with PTDM-2/siN1 orPTDM-2/siCont. b) Relative Notch 1 expression in T_(H)1 polarized CD4⁺Tcells 48 h after treatment with PTDM-2/siN1 or PTDM-2/siCont. c) Flowcytometry analysis showing T_(H)1 polarized CD4⁺T cells stained withfluorescent PE-anti Notch 1 48 h after treatment with siRNA complexes;blue curve: PTDM-2/siN1 treated cells, green curve: PTDM-2/siCont, redsolid curve: untreated cells. d) Percentage of T-bet expressing T_(H)1polarized CD4⁺T cells 48 h after treatment with PTDM-2/siN1 orPTDM-2/siCont. e) Relative T-bet expression in T_(H)1 polarized CD4⁺Tcells 48 h after treatment with PTDM-2/siN1 or PTDM-2/siCont. f) Flowcytometry analysis showing T_(H)1 polarized CD4⁺T cells stained withfluorescent Alexa Fluor 647 anti-T-bet 48 h after treatment with siRNAcomplexes; blue curve: PTDM-2/siN1 treated cells, green curve:PTDM-2/siCont, red solid curve: untreated cells. g-i) Flow cytometryanalysis showing T_(H)1 polarized CD4⁺T cells stained with fluorescentAPC-anti IFN-γ 48 h after treatment with siRNA complexes; (g) untreatedcells, (h) PTDM-2/siCont treated cells, (i) PTDM-2/siN1 treated cells.j) Percentage of IFN-γ expressing T_(H)1 polarized CD4⁺T cells 48 hafter treatment with PTDM-2/siN1 or PTDM-2/siCont. k) Relative IFN-γexpression in T_(H)1 polarized CD4⁺T cells 48 h after treatment withPTDM-2/siN1 or PTDM-2/siCont. Results are representative of twoindependent replicates.

FIG. 50: Untreated human PBMCs were polarized under T_(H)1 conditionsfor 48 h. a) Live population was gated on side scatter (SSC) and forwardscatter (FCS) dot plot. b) CD4⁺T cells were gated on live populationaccording to their reactivity to PerCP-Cy5.5-labeled anti-CD4. c) Notch1 expressing CD4⁺T cells were identified according to their reactivityto PE-labeled anti-Notch 1. d) T-bet expressing CD4⁺T cells wereidentified according to their reactivity to eFluor 660-labeledanti-T-bet.

FIG. 51: PTDM-2/siN1 treated human PBMCs were polarized under T_(H)1conditions for 48 h. a) Live population was gated on side scatter (SSC)and forward scatter (FCS) dot plot. b) CD4⁺T cells were gated on livepopulation according to their reactivity to PerCP-Cy5.5-labeledanti-CD4. c) Notch 1 expressing CD4⁺T cells were identified according totheir reactivity to PE-labeled anti-Notch 1. d) T-bet expressing CD4⁺Tcells were identified according to their reactivity to eFluor660-labeled anti-T-bet.

FIG. 52: PTDM-2/siCont treated human PBMCs were polarized under T_(H)1conditions for 48 h. a) Live population was gated on side scatter (SSC)and forward scatter (FCS) dot plot. b) CD4⁺T cells were gated on livepopulation according to their reactivity to PerCP-Cy5.5-labeledanti-CD4. c) Notch 1 expressing CD4⁺T cells were identified according totheir reactivity to PE-labeled anti-Notch 1. d) T-bet expressing CD4⁺Tcells were identified according to their reactivity to eFluor660-labeled anti-T-bet.

FIG. 53: Untreated human PBMCs were polarized under T_(H)1 conditionsfor 72 h. a) Live population was gated on side scatter (SSC) and forwardscatter (FCS) dot plot. b) CD4⁺T cells were gated on live populationaccording to their reactivity to PerCP-Cy5.5-labeled anti-CD4. c) Notch1 expressing CD4⁺T cells were identified according to their reactivityto PE-labeled anti-Notch 1. d) T-bet expressing CD4⁺T cells wereidentified according to their reactivity to eFluor 660-labeledanti-T-bet.

FIG. 54: PTDM-2/siN1 treated human PBMCs were polarized under T_(H)1conditions for 72 h. a) Live population was gated on side scatter (SSC)and forward scatter (FCS) dot plot. b) CD4⁺T cells were gated on livepopulation according to their reactivity to PerCP-Cy5.5-labeledanti-CD4. c) Notch 1 expressing CD4⁺T cells were identified according totheir reactivity to PE-labeled anti-Notch 1. d) T-bet expressing CD4⁺Tcells were identified according to their reactivity to eFluor660-labeled anti-T-bet.

FIG. 55: PTDM-2/siCont treated human PBMCs were polarized under T_(H)1conditions for 72 h. a) Live population was gated on side scatter (SSC)and forward scatter (FCS) dot plot. b) CD4⁺T cells were gated on livepopulation according to their reactivity to PerCP-Cy5.5-labeledanti-CD4. c) Notch 1 expressing CD4⁺T cells were identified according totheir reactivity to PE-labeled anti-Notch 1. d) T-bet expressing CD4⁺Tcells were identified according to their reactivity to eFluor660-labeled anti-T-bet.

DEFINITIONS

Definitions of specific functional groups and chemical terms aredescribed in more detail below. General principles of organic chemistry,as well as specific functional moieties and reactivity, are described in“Organic Chemistry”, Thomas Sorrell, University Science Books,Sausalito: 1999.

Certain compounds of the present invention may exist in particulargeometric or stereoisomeric forms. The present invention contemplatesall such compounds, including cis- and trans-isomers, R- andS-enantiomers, diastereomers, (D)-isomers, (L)-isomers, the racemicmixtures thereof, and other mixtures thereof, as falling within thescope of the invention. Additional asymmetric carbon atoms may bepresent in a substituent such as an alkyl group. All such isomers, aswell as mixtures thereof, are intended to be included in this invention.

Isomeric mixtures containing any of a variety of isomer ratios may beutilized in accordance with the present invention. For example, whereonly two isomers are combined, mixtures containing 50:50, 60:40, 70:30,80:20, 90:10, 95:5, 96:4, 97:3, 98:2, 99:1, or 100:0 isomer ratios arecontemplated by the present invention. Those of ordinary skill in theart will readily appreciate that analogous ratios are contemplated formore complex isomer mixtures.

If, for instance, a particular enantiomer of a compound of the presentinvention is desired, it may be prepared by asymmetric synthesis, or byderivation with a chiral auxiliary, where the resulting diastereomericmixture is separated and the auxiliary group cleaved to provide the puredesired enantiomers. Alternatively, where the molecule contains a basicfunctional group, such as amino, or an acidic functional group, such ascarboxyl, diastereomeric salts are formed with an appropriateoptically-active acid or base, followed by resolution of thediastereomers thus formed by fractional crystallization orchromatographic methods well known in the art, and subsequent recoveryof the pure enantiomers.

Given the benefit of this disclosure, one of ordinary skill in the artwill appreciate that synthetic methods, as described herein, may utilizea variety of protecting groups. By the term “protecting group”, as usedherein, it is meant that a particular functional moiety, e.g., O, S, orN, is temporarily blocked so that a reaction can be carried outselectively at another reactive site in a multifunctional compound. Inpreferred embodiments, a protecting group reacts selectively in goodyield to give a protected substrate that is stable to the projectedreactions; the protecting group should be selectively removable in goodyield by preferably readily available, non-toxic reagents that do notattack the other functional groups; the protecting group forms an easilyseparable derivative (more preferably without the generation of newstereogenic centers); and the protecting group has a minimum ofadditional functionality to avoid further sites of reaction. Oxygen,sulfur, nitrogen, and carbon protecting groups may be utilized. Examplesof a variety of protecting groups can be found in Protective Groups inOrganic Synthesis, Third Ed. Greene, T. W. and Wuts, P. G., Eds., JohnWiley & Sons, New York: 1999.

It will be appreciated that the compounds, as described herein, may besubstituted with any number of substituents or functional moieties.

As used herein, (C_(x)-C_(y)) refers in general to groups that have fromx to y (inclusive) carbon atoms. Therefore, for example, C₁-C₆ refers togroups that have 1, 2, 3, 4, 5, or 6 carbon atoms, which encompassC₁-C₂, C₁-C₃, C₁-C₄, C₁-C₅, C₂-C₃, C₂-C₄, C₂-C₅, C₂-C₆, and all likecombinations. (C₁-C₂₀) and the likes similarly encompass the variouscombinations between 1 and 20 (inclusive) carbon atoms, such as (C₁-C₆),(C₁-C₁₂) and (C₃-C₁₂).

As used herein, the term “(C_(x)-C_(y))alkyl” refers to a saturatedlinear or branched free radical consisting essentially of x to y carbonatoms, wherein x is an integer from 1 to about 10 and y is an integerfrom about 2 to about 20. Exemplary (C_(x)-C_(y))alkyl groups include“(C₁-C₂₀)alkyl,” which refers to a saturated linear or branched freeradical consisting essentially of 1 to 20 carbon atoms and acorresponding number of hydrogen atoms. Exemplary (C₁-C₂₀)alkyl groupsinclude methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,dodecanyl, etc. Of course, other (C₁-C₂₀)alkyl groups will be readilyapparent to those of skill in the art given the benefit of the presentdisclosure.

DESCRIPTION OF THE INVENTION

The invention is based in part on the discovery that, unlike certainknown PTDs (e.g., heptaarginine and polyarginine) that requirecounterion for activation, a number of novel guanidinium-containingpolymers and block copolymers are self-activating in anion transportacross lipid bilayers.

In one aspect, the invention generally relates to a block co-polymerhaving the Formula of (I):

wherein

-   -   X₁, X₂ each is independently O, CH₂ or substituted CH₂;    -   Y₁₁, Y₁₂ each is independently a single bond or a linking group;    -   Z₁₁, Z₁₂ each is independently hydrogen, or an —N(R_(z))₂,        alkyl, substituted alkyl, aryl, substituted aryl group, with the        proviso that at least one of Z₁₁ and Z₁₂ comprises N(R_(z))₂ or

-   -   Y₂₁, Y₂₂ each is independently a single bond or a linking group;    -   Z₂₁, Z₂₂ each is independently hydrogen, an —OR_(z), alkyl,        substituted alkyl, aryl, substituted aryl group;    -   R_(z) each is independently hydrogen, an alkyl, substituted        alkyl, aryl, substituted aryl, poly(ethylene oxide) group;    -   R is hydrogen, a C₁-C₆ alkyl group or a poly(ethylene oxide)        group; and    -   m, n each is independently an integer from about 2 to about 300.

In certain embodiments, m and n are independently integers from about 2to about 50, for example from about to about 24, from about 6 to about20, from about 8 to about 16 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24). In certain embodiments,one or both m and n is 25 or greater, 30 or greater, 40 or greater.

In certain embodiments of the block co-polymer, each of X₁ and X₂ is O;each of Y₁₁ and Y₁₂ is independently a linking group comprising acarbonyl group; each of Z₁₁ and Z₁₂ comprises

each of Y₂₁ and Y₂₂ is independently a linking group comprising acarbonyl group; each of Z₂₁, Z₂₂ is —OR_(z), wherein at least one—OR_(z) comprises an aryl group; each R is hydrogen; and each of m and nis selected from an integer from about 2 to about 24.

In certain embodiments of the block co-polymer, each of X₁ and X₂ is O;each of Y₁₁ and Y₁₂ is independently a linking group comprising acarbonyl group; each of Z₁₁ and Z₁₂ comprises N(R_(z))₂; each of Y₂₁ andY₂₂ is independently a linking group comprising a carbonyl group; eachof Z₂₁, Z₂₂ is —OR_(z), wherein at least one —OR_(z) comprises an arylgroup; each R is hydrogen; and each of m and n is selected from aninteger from about 2 to about 24.

In certain embodiments of the block co-polymer, each of X₁ and X₂ isCH₂; each of Y₁₁ and Y₁₂ is independently a linking group comprising acarbonyl group; one of Z₁₁ and Z₁₂ comprises

each of Y₂₁ and Y₂₂ is independently a linking group comprising acarbonyl group; each of Z₂₁, Z₂₂ is —OR_(z), wherein at least one—OR_(z) comprises an aryl group; each R is hydrogen; and each of m and nis selected from an integer from about 2 to about 24.

In certain embodiments of the block co-polymer, each of X₁ and X₂ isCH₂; each of Y₁₁ and Y₁₂ is independently a linking group comprising acarbonyl group; one of Z₁₁ and Z₁₂ comprises N(R_(z))₂; each of Y₂₁ andY₂₂ is independently a linking group comprising a carbonyl group; eachof Z₂₁, Z₂₂ is —OR_(z), wherein at least one —OR_(z) comprises an arylgroup; each R is hydrogen; and each of m and n is selected from aninteger from about 2 to about 24.

In certain embodiments of the block co-polymer, each of Y₁₁, Y₁₂, Y₂₁and Y₂₂ is independently a linking group comprising a carbonyl group andcomprising a —O(CH₂)_(q)— or a —O(CH₂)_(q)—, wherein each q isindependently an integer from about 1 to about 6 (e.g., 1, 2, 3, 4, 5,6).

In certain embodiments, the block co-polymer is a component of acomposition. The composition may further include a therapeutic agenthaving a biological effect under physiological conditions. Thetherapeutic agent may be a small molecule compound, a peptide, anantibody, a protein or a nucleic acid.

In certain embodiments, the block co-polymer is a component of acomposition. The composition may further include a diagnostic agentcapable of emitting a detectable signal. The diagnostic agent mayinclude a fluorescent label, a radioactive label, or a quantum dot oflabel.

In another aspect, the invention generally relates to a composition thatincludes: a polymer having a structural unit of Formula (II):

-   -   wherein    -   X₁ is independently O, CH₂ or substituted CH₂;    -   Y₁₁, Y₁₂ each is independently a single bond or a linking group;    -   Z₁₁, Z₁₂ each is independently hydrogen, or an —N(R_(z))₂,        alkyl, substituted alkyl, aryl, substituted aryl group, with the        proviso that a least one of Z₁₁ and Z₁₂ comprises —N(R_(z))₂ or

-   -   R_(z) each is independently hydrogen, an alkyl, substituted        alkyl, aryl, substituted aryl, poly(ethylene oxide) group;    -   R is hydrogen, a C₁-C₆ alkyl group, or a poly(ethylene oxide);        and    -   n is independently an integer from about 2 to about 300; and        a therapeutic agent having a biological effect under        physiological conditions.

In certain embodiments, n is an integer from about 2 to about 50, forexample from about to about 24, from about 6 to about 20, from about 8to about 16 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24). In certain embodiments, one or both mand n is 25 or greater, 30 or greater, 40 or greater.

In some embodiments of the composition, the therapeutic agent comprisesa small molecule compound. In some embodiments of the composition, thetherapeutic agent comprises a peptide. In some embodiments of thecomposition, the therapeutic agent comprises an antibody. In someembodiments of the composition, the therapeutic agent comprises aprotein. In some embodiments of the composition, the therapeutic agentcomprises a nucleic acid.

In some embodiments of the composition, the polymer comprises astructural unit selected from:

wherein each X is independently a counter anion.

In some embodiments of the composition, the polymer comprises astructural unit of the formula:

Each of Y_(u) and Y₁₂ may be independently a linking group that includesa carbonyl group and —O(CH₂)_(q)—, wherein q is an integer from about 1to about 6 (e.g., 1, 2, 3, 4, 5, 6).

In some embodiments, each of m and n is an integer from about 4 to about16.

In another aspect, the invention generally relates to a compositioncomprising: a polymer having a monomer of Formula (II):

-   -   wherein    -   X₁ is independently O, CH₂ or substituted CH₂;    -   Y₁₁, Y₁₂ each is independently a single bond or a linking group;    -   Z₁₁, Z₁₂ each is independently hydrogen, an —N(R_(z))₂, alkyl,        substituted alkyl, aryl, substituted aryl group, with the        proviso that a least one of Z₁₁ and Z₁₂ comprises —N(R_(z))₂ or

-   -   R_(z) each is independently hydrogen, an alkyl, substituted        alkyl, aryl, substituted aryl, poly(ethylene oxide) group;    -   R is hydrogen, a C₁-C₆ alkyl group or a poly(ethylene oxide);        and    -   n is independently an integer from about 2 to about 300; and        a diagnostic agent capable of emitting a detectable signal.

In some embodiments of the composition, the diagnostic agent includes afluorescent label. In some embodiments of the composition, thediagnostic agent includes a radioactive label. In some embodiments ofthe composition, the diagnostic agent includes a quantum dot label.

In some embodiments, the composition includes the polymer comprising astructural unit selected from:

wherein each X is independently a counter anion.

Y₁₁ and Y₁₂ may be independently a linking group comprising a carbonylgroup and comprising a —O(CH₂)_(q)— or a —O(CH₂)_(q)—, wherein q is aninteger from about 1 to about 6. Each of m and n may be an integer fromabout 4 to about 16, for example.

The therapeutic or diagnostic agent may be covalently bonded to ornon-covalently associated with the polymer of the invention.

In yet another aspect, the invention generally relates to a blockco-polymer having the Formula of (III):

-   -   wherein    -   X₁, X₂ each is independently O, CH₂ or substituted CH₂;    -   Y₁ is a linking group;    -   Z₁ is comprises —N(R_(z))₂ or

-   -   Y₂ is a single bond or a linking group;    -   Z₂ is hydrogen, an alkyl or substituted alkyl group;    -   R_(z) is hydrogen, an alkyl, substituted alkyl, aryl,        substituted aryl group;    -   R is hydrogen, a C₁-C₁₂ alkyl group or a poly(ethylene oxide)        group; and    -   m, n each is independently an integer from about 2 to about 300.

In certain embodiments, m and n are independently integers from about 2to about 50, for example from about to about 24, from about 6 to about20, from about 8 to about 16 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24). In certain embodiments,one or both m and n is 25 or greater, 30 or greater, 40 or greater.

In some embodiments of the block co-polymer, each of X₁ and X₂ is O; Y₁is a linking group comprising a carbonyl group; Y₂ is a single bond; Z₁comprises

Z₂ is R; each R is hydrogen, an alkyl or substituted alkyl group; andeach of m and n is selected from an integer from about 4 to about 24.

In some embodiments of the block co-polymer, each of X₁ and X₂ is O; Y₁is a linking group comprising a carbonyl group; Y₂ is a single bond; Z₁comprises —N(R_(z))₂; Z₂ is R; each R is hydrogen, an alkyl orsubstituted alkyl group; and each of m and n is selected from an integerfrom about 4 to about 24.

In some embodiments of the block co-polymer, each of X₁ and X₂ is O;each of Y₁ and Y₂ is a linking group comprising a carbonyl group; Z₁comprises

Z₂ comprises —N(R_(z))₂; each R is hydrogen, an alkyl or substitutedalkyl group; and each of m and n is selected from an integer from about4 to about 24.

In certain embodiments, the block co-polymer has the formula of:

wherein R₂ is a C₁-C₁₂ alkyl or substituted alkyl group, an aryl orsubstituted aryl group, or a poly(ethylene oxide) group; X is a counteranion.

In yet another aspect, the invention generally relates to a blockcopolymer that includes the structural unit of the formula:

wherein X is a counter anion.

In certain embodiments, the block co-polymer may further include astructural unit of the formula:

wherein R_(L) is a —(CH₂)_(q)—, wherein q is an integer from about 1 toabout 6 (e.g., 1, 2, 3, 4, 5, 6).

In certain embodiments, the block co-polymer may further include astructural unit of the formula:

In yet another aspect, the invention generally relates to a compositionthat includes: a polymer having a structural unit of Formula (IV):

-   -   wherein    -   X₁ is O, CH₂ or substituted CH₂;    -   Y₁ is a linking group;

Z₁ is comprises —N(R_(z))₂ or

-   -   R_(z) is hydrogen, an alkyl, substituted alkyl, aryl,        substituted aryl group;    -   R is hydrogen or a C₁-C₁₂ alkyl group or a poly(ethylene oxide)        group; and    -   n is independently an integer from about 2 to about 300.        a therapeutic agent having a biological effect under        physiological conditions.

In some embodiments of the composition, the therapeutic agent is a smallmolecule compound. In some embodiments of the composition, thetherapeutic agent is a peptide. In some embodiments of the composition,the therapeutic agent is an antibody. In some embodiments of thecomposition, the therapeutic agent is a protein. In some embodiments ofthe composition, the therapeutic agent a nucleic acid.

In certain embodiments, the polymer comprises a structural unit of theformula:

wherein X is a counter anion.

In yet another aspect, the invention generally relates to a compositionthat includes a polymer comprising a structural unit of Formula (IV):

-   -   wherein    -   X₁ is O, CH₂ or substituted CH₂;    -   Y₁ is a linking group;    -   Z₁ is comprises —N(R_(z))₂ or

-   -   R_(z) is hydrogen, an alkyl, substituted alkyl, aryl,        substituted aryl group;    -   R is hydrogen or a C₁-C₁₂ alkyl group or a poly(ethylene oxide)        group; and    -   n is independently an integer from about 2 to about 300.        a diagnostic agent capable of emitting a detectable signal.

In some embodiments of the composition, the diagnostic agent includes afluorescent label. In some embodiments of the composition, thediagnostic agent includes a radioactive label. In some embodiments ofthe composition, the diagnostic agent includes a quantum dot label.

In certain embodiments, the polymer comprises a structural unit of theformula:

wherein X is a counter anion.

With this understanding of PTD activity as background, the cellularuptake properties of the guanidinium-rich structures shown in FIG. 1were designed, synthesized and studied. In order to track the polymersinside cells, they were labeled with a green fluorescent molecule,7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD), by apost-functionalization method. (Roberts, et al. 2004 Org. Lett. 63,253-3255.) Since most PTDs have relatively short sequences, the choiceof dye molecule is important, as it can significantly impact the overallmolecular structure. Recently, the effect of fluorescein on cellularuptake and distribution of an octaarginine (R8) derivative wasdescribed. In the presence of the fluorescein tag, these R8 derivativeswere observed in both the cytoplasm and nucleus. Without fluorescein,however, only punctuate cytoplasmic staining was observed. (Puckett, etal. 2009 J. Am. Chem. Soc. 131, 8738-8739.) This is an illustrativeexample on how the addition of a large dye molecule can easily alter thecellular uptake properties of a molecular transporter. NBD was chosen asit is one of the smallest dyes available and, therefore, has a limitedimpact on the internalization activity of these polymers (FIG. 33).

In addition to evaluating the importance of chain length oninternalization efficiency, this synthetic scaffold also allows us tostudy the effect of ‘guanidine density’ on intracellular uptake in a waythat previous structures could not. For example, FIG. 1 shows twochemical structures, Mn and Dn, in which two sequences with the samechain length (n=degree of polymerization) were prepared but those basedon Dn have twice the density of guanidine groups as those based on Mn.Testing these newly designed PTDMs in three different cell lines,HEK293T, CHO and Jurkat T cells, demonstrated internalization wasuniversal, while the best synthetic transporter showed a smalldependence on cell type. Internalization assays at 4° C. highlighted thepresence of energy- and temperature-independent pathways, implying thatthese PTDMs may be excellent delivery vectors as they avoid theendosomal entrapment which is known to decrease the efficiency andbioavailability of both the transporters and the cargo. (Cheung, et al.2009 J Control Release 137, 2-7; Abes, et al. 2006 J Control Release110, 595-604.) These results demonstrate that it is possible tointroduce biological character to synthetic polymers so that they canact like PTDs and, in fact, are more efficient than one of the bestpeptides, R9.

Arginine-rich structures are known to translocate across the plasmamembrane. It is demonstrated by this invention that it is possible toprogram synthetic polymers to behave like natural PTDs. Using ROMP,novel sequences were designed to study the structure-activityrelationship (SAR) between guanidinium functionalized polymers andcellular internalization in three different cell types. ROMP was chosenbecause it is well-known to be functional group tolerant, and it is aliving polymerization method, which allows the number average degree ofpolymerization to be narrowly defined and easily controlled. Here, twonovel structural classes of new PTDMs were introduced, Mn and Dn. Thesetwo structural classes allow the distinction of total charge density, orthe total number of guanidinium functions, from molecular length. Forexample, within the group M9, D5 and D9, one can compare the number ofguanidines (M9 vs D5) or the total length (M9 vs D9) (FIG. 5).Specifically, the ability to prepare peptides with the same overalllength but twice the functional group density is non-trivial. Whilecationic sequences can be cytotoxic, 7-AAD assays determined that allthe internalization studies were conducted below any concentrations thatinfluenced cell viability.

To better analyze the internalization efficiencies of these PTDMs andtheir affinities for the cell membrane, fluorescence from cell surfacebound molecules was quenched using the established NBD-dithionite assayand data collected both for treated and untreated cells. Percentcellular uptake, the ratio of mean fluorescence intensity per cell fromcell populations treated with dithionite (only internalizationfluorescence) to cells not treated with dithionite (both internal andsurface bound fluorescence) were measured. This highlights the importantparameters related to the transport ability of these PTDMs. By examiningthis percent cellular uptake rather than simply mean fluorescence percell for each molecule, a more direct measure of internalizationefficiency is obtained since the raw data clearly shows that somestructures bind to the cellular surface more strongly and as a resultthe concentration of PTDMs at the surface are proportionally higher.

The internalization mechanism of arginine rich PTDs has been reported asmainly endocytosis in which the encapsulation in endocytotic vesicles isa major restriction to the use of these peptides in cytosolic-,nuclear-, and organelle-specific delivery. (Cheung, et al. 2009 J.Control Release 137, 2-7; Abes, et al. 2006 J. Control Release 110,595-604.) In the case of endocytotic pathways, transporter molecules aretrapped inside endosomes/lysosomes in an environment with an acidic pHand digestive enzymes that inhibit the capability of transportermolecules to deliver their cargo. To explore the internalization ofthese novel PTDMs, uptake was examined at 37° C. and 4° C. as well as bymicroscopy and colocalization with lysotracker red-99. Internalizationwas generally higher at 37° C. than 4° C., which is consistent with theliterature and a reasonable observation since endocytotic pathways wouldbe operative. This is confirmed by the microscopy studies shown in FIG.4. However, and importantly, significant internalization is observed at4° C. demonstrating that these novel PTDMs also exploitenergy-independent pathways. In the Dn series, percent cellular uptakefor CHO and Jurkat T-cells is generally similar at 37° C. and 4° C.,indicating these PTDMs efficiently access energy- andtemperature-independent pathways (see FIG. 3). It should be noted thatin Jurkat T-cells, D9 is twice as efficient at 4° C. compared to 37° C.,which highlights the role of polymer chemistry and demonstrates theimportance of establishing a SAR. In agreement, the overlaid image inFIG. 4c shows distinct regions of only green emission associated withthe presence of PTDMs outside of endosomes. This improved uptake of theDn PTDMs, especially at 4° C., implies that not only the presence butalso the density of guanidine units influences uptake pathways, and thata greater density of guanidine units can optimize internalization viaenergy- and temperature-independent pathways. The fact that the best inclass PTDM varies among cell lines further demonstrates the value ofthis versatile synthetic platform. (Mueller, et al. 2008 Bioconj. Chem.19, 2363-2374.) For example, examining percent cellular uptake at 37° C.shows that D5 and D9 are better than M9 in HEK293T cells while D5 isbetter than M9 and D9 in CHO cells but M9 is superior in Jurkat T cells(FIG. 5).

The invention thus enables the design and syntheses of syntheticpolymers mimic natural PTDs by introducing the appropriatefunctionality. These synthetic structures demonstrated superior uptakeefficiencies compared to a well-known peptide analogue. Taken together,these synthetic analogs are highly efficient novel transporter moleculeswith important applications in the delivery of bioactive macromolecules.

EXAMPLES Synthetic Mimics of Protein Transduction Domains Synthesis ofPTDMs

Monomers for PTDMs were prepared in three steps. The first step was theDiels-Alder reaction of maleic anhydride and furan. In the second step,product from step 1 was reacted with the corresponding alcohol (methanolor 1,3-Di-Boc-2-(2-hydroxyethyl)guanidine) and the reaction wascatalyzed by DMAP. Finally, 1,3-Di-Boc-2-(2-hydroxyethyl)guanidine wasadded to the monomer by EDC coupling (see Supplementary Information fordetails). Boc-protected guanidinine functionalized monomers werepolymerized via Grubb's 3^(rd) generation catalyst (see Supplementaryinfo for details).

Uptake of PTDMs:

HEK293T and CHO cells were treated with 5 μM NBD-labeled PTDMs, andJurkat T cells were treated with 2.5 μM NBD-labeled PTDMs for 30 min incomplete growth medium supplemented with 10% fetal bovine serum. Then,the cellular uptake of the molecules was analyzed by fluorescenceactivated cell sorter (FACS-BD-LSRII) or confocal microscopy(LSM510-Carl Zeiss, 40× oil immersion objective) (see SupplementaryInformation for details).

Synthesis of NBD-Labeled Polymers

Di-Boc protected guanidinium functionalized monomers were synthesized inthree steps and resulted in ˜80% overall yield. This synthetic monomerdesign allowed us to introduce one guanidinium group, as a directcomparison to R9, or two guanidinium groups, which doubled thefunctional group density. In order to visualize these PTDMs withincells, they were end-labeled by first ring-opening asuccinimide-functionalized activated ester monomer, then adding eitherthe methyl or diguanidinium monomer units. (Roberts, et al. 2004 Org.Lett. 63, 253-3255.) Following polymerization, the succinimide ester wasexchanged with an ethylenediamine functionalized NBD dye, and thepolymers were purified by both dialysis and column chromatography. Thelabeled polymers were characterized by NMR and UV-capable size exclusionchromatography. Analysis of the Boc-protected polymers yielded theexpected molecular weights and narrow polydispersities (PDI˜1.06-1.10),which are typical of ROMP due to its living nature. (Choi, et al. 2003Angew. Chem. Int. Ed. 42, 1743-1746.) In the last step, the Boc groupswere removed using trifluoroacetic acid in dichloromethane. The finalproducts were purified by dialysis and recovered by lyophilization.Though, ester groups present in the polymers could undergo hydrolysis,this would be unexpected, as the time scale of these in vitroexperiments is short (˜30 mins) compared to the room temperaturestability in buffer (PBS, pH 7.2) (>2 weeks) so hydrolysis in thepresence of cells has therefore not been investigated

Cellular Uptake Assays

To avoid artifacts from the cellular uptake experiments, severalprecautions were taken. Early studies on PTDs documented artifacts thatresult from cells being fixed prior to quantification. (Thoren, et al.2003 Biochem. Biophys. Res. Comm. 307, 100-107.) Therefore, cellfixation, which is unnecessary, was not used. Further, in order tomeasure only the fluorescence from internalized molecules, theNBD-dithionite assay was employed to quench any cell surface boundfraction remaining after the last washing step. (Drin, et al. 2003 JBiol. Chem., 278, 31192-31201.) After quenching the cell surface boundmolecules, NBD-labeled molecules were detected in more than 80% of thecells at 5 μM, as shown in FIG. 2a by a representative FACS histogram.The relative internalization efficiency of NBD-labeled molecules wasdemonstrated using both the mean fluorescence per cell and percentcellular uptake. FIG. 2b shows the impact of Dn polymer length comparingthe mean fluorescence between cell associated (prior to dithionitetreatment, open bars) and internalized molecules (following surfacebound NBD quenching, closed bars).

As the PTDM length increased, the number of both internalized and cellsurface bound molecules increased. For example, D18 is twice as long asD9, and D18 is two-fold more efficient than D9 in terms of theinternalized fluorescence intensity. On the other hand, there is a10-fold increase in the cell surface bound fraction, indicating that D18interacts with the cell surface much more strongly than D9, but it isnot internalized as efficiently. The mean fluorescence intensity ofinternalized molecules provides information regarding uptake ofmolecules, however more information is needed to develop a detailed SARfor PTDMs that efficiently cross the plasma membrane.

In the simplest form of this process (ignoring biological processes likeendocytosis), there are at least two important, yet different,equilibrium constants that need to be considered: ratio of PTDM insolution to cell surface bound PTDM and ratio of cell surface bound PTDMto internalized PTDM. Because of interest in the second process, thedata has been normalized as the percent cellular uptake, which is thepercent ratio of internalized molecules (following dithionite treatment)to total cell associated molecules (before dithionite treatment). Thisratio is conceptually demonstrated in FIG. 2b by the solid red bars andopen red bars for each PTDM. This normalized value then allows directcomparisons among all PTDMs and across all cell types to be made. Thismethod was chosen to present the data because this ratio is a moreaccurate way to understand the internalization efficiency of each PTDM,and because it separates internalization from cell surface bindingaffinity. This would be unnecessary if every molecule had the sameaffinity for the cell surface, but as shown by the mean fluorescencedata, this is not true. As a result, despite the identicalconcentrations in solution, the concentration at the cell surface varieswith molecular structure and cell type. Therefore, the figures afterFIG. 2b report the percent cellular uptake, focusing on the PTDMs thatare the most efficient at crossing the membrane.

Initially, the PTDMs Mn and Dn, with various molecular weights, wereevaluated for uptake in HEK293T cells (FIG. 2) along with the controlR9. These data clearly demonstrate that the methyl- and di-guanidiniumpolymers were able to function as PTDMs and, in fact, showed greaterinternalization efficiency than the thoroughly studied control R9.(Mitchell, et al. 2000 J. Peptide Res., 56, 318-325; Futaki, et al. 2001J Biol. Chem. 276, 5836-5840; Wender, et al. 2000 Proc. Natl. Acad. Sci.USA 97, 13003-13008.) Within the Mn series, the maximum efficiency wasobserved with 12 repeat units (M12) when compared to 9 (M9) and 18 (M18)(FIG. 2d ). On the other hand, in the Dn series, which has double thenumber of guanidinium groups compared to the Mn series, the mostefficient PTDMs have lengths of 5 and 9 repeat units (D5 and D9,respectively) (FIG. 2f ). The fact that D5, D9, and M12 show similarinternalization efficiencies suggests that the number of guanidiniumgroups is not the only factor affecting cellular uptake, and that thedensity of guanidinium groups also plays an important role. Experimentswere also conducted at 4° C. (FIGS. 2c and 2e ) to inhibitenergy-dependent pathways. Experiments at 37° C. showed that theguanidinium density affects the internalization and the experiments at4° C. demonstrated this even more clearly. As shown in FIGS. 2c and 2e ,at lower temperature, Dn molecules are much more efficient than their Mnanalogues. For example, D9 showed 35% cellular uptake compared to 10%for M18, although the total number of guanidinium groups is the same.Among all the PTDMs, D9 showed superior uptake at 4° C., making it themost favorable molecule for internalization by non-endocytotic pathways(FIG. 2e ).

In addition to cellular uptake experiments at 37° C. and 4° C.,cytotoxicity testing was also performed using 7-amino-actinomycin D(7-AAD) viability dye to determine lethal concentrations (LC₅₀). Tobuild a structure-activity relationship, plots were made of percentcellular uptake vs. LC₅₀ and the graph was divided into four quadrants(FIG. 30). Optimal PTDMs would be those structures with highinternalization efficacy and high LC₅₀ values, or low toxicity (quadrantII). All the molecules in quadrants I and II in FIGS. 30a and 30b wereconsidered promising PTDMs for further study since they showed both lowtoxicity and good cellular uptake. In addition, all of the PTDMsreported here showed no toxicity in the working concentration range.

To expand the cell types examined, the PTDMs specified as most effectivein HEK293T cells were evaluated for internalization in both CHO andJurkat T cells. FIG. 3a shows that in CHO cells, the shorter PTDMs, D5and M9 were more efficient than their longer analogs, D9 and M12. D9 andM12 were found to adsorb more strongly on the cell membrane, but theirability to enter the cells was limited with internalization efficienciesnear 35%, compared to M9 and D5 which had efficiencies of 55% and 65%,respectively. PDTM D5 demonstrated remarkable uptake in this cell typeat both high and low temperatures, in contrast to its low uptake inHEK293T cells. The addition of eight more guanidinium groups (in thecase of D9) did not increase the uptake in CHO cells at 37° C. nor 4° C.but, in fact, reduced the percent of internalized molecules whileenhancing the cell surface binding compared to D5. Furthermore, M9 andD5 have essentially the same number of guanidinium groups and exhibitedsimilar uptake characteristics at 37° C. (FIG. 3a ). Nevertheless, D5remained the best in class with a slightly higher internalizationpercentage at 37° C. and a significantly higher internalizationpercentage at 4° C. (60% vs. 30%). Similar to the observations with theHEK293T cells, the Dn-series PTDMs entered CHO cells more efficiently at4° C. than the Mn-series.

Jurkat T cells were found to be more sensitive to changes in the densityof guanidinium group and the chain length. For example, D9 and M12demonstrated considerable toxicity, even at low concentrations like 5μM. As a result, and in contrast to the other cell studies, all of theuptake studies with these suspension cells were performed at a lowerconcentration of 2.5 μM. The shorter sequences, D5 and M9, remained moreefficient, showing better uptake profiles at both high and lowtemperatures (FIGS. 3c and d ), while D9 and M12 showed a high affinityfor the cell surface (FIGS. 26 and 27). In this T cell line, M9exhibited outstanding uptake at 37° C. (60%), which was slightlydiminished at 4° C. (50%) yet still comparable to D5. The importance ofincreased guanidinium density (Dn vs. Mn) is emphasized at 4° C. as thepercent cellular uptake of D5 remained 40% at both 37° C. and 4° C.,while the uptake of M9 decreased from 60% to 50% upon reducing thetemperature. D9 was more efficient at 4° C. than at 37° C. (32% vs.16%), showing the importance of guanidinium density on theenergy-independent internalization pathway.

Although the detailed mechanism of cellular internalization is beyondthe scope of this paper, some insight into the cellular location ofthese PTDMs is warranted. The internalization efficiency at 37° C.compared to 4° C. implies that energy-independent mechanisms areoperative with these novel, synthetic PTDMs. To further explore theirinternalization, the presence of D9 in CHO cells was visualized usingconfocal microscopy. As shown in FIG. 4a , all of the cells within thefield contain significant green fluorescence from the NBD labeled PTDM.Simultaneously, LysoTracker® Red DND-99 was employed to stain endosomicvesicles present in these CHO cells as shown in FIG. 4b and the overlaidimage (FIG. 4c ) shows yellow areas where D9 and LysoTracker® Red DND-99are colocalized in the endosomes/lysosomes. FIG. 4c also shows uniformdiffuse green cytoplasmic staining within the cell, indicating thepresence of D9 outside of endosomic vesicles.

Experimental General

Maleic anhydride, furan, 4-dimethyl aminopyridine (DMAP),1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC),methanol, 1,3-Di-Boc-2-(2-hydroxyethyl)guanidine, anhydrousdimethylformamide (DMF), di-isopropyl ethyl amine (DIPEA), ethylvinylether and trifluoroacetic acid (TFA) were obtained as reagent grade fromAldrich, Fluka or Acros and used as received.

3^(rd) generation Grubbs catalyst(Dichloro-di(3-bromopyridino)-N,N′-Dimesitylenoimidazolino-Ru═CHPh; G3)was synthesized as described previously by Grubbs et al. (Love, et al.2002 Angew. Chem. Int. Ed. 41, 4035-4037.) The HPLC grade solvents ethylacetate, pentane and hexane were purchased from Aldrich, FisherScientific or Acros and used as received. Tetrahydrofuran (THF) (HPLCgrade, Fisher Scientific) was distilled from sodium/benzophenone undernitrogen. Dichloromethane (DCM) (HPLC grade, Fisher Scientific) wasdistilled from CaH₂ under nitrogen.

Gel permeation chromatography (THF, calibrated with polystyrenestandards, toluene as flow marker, 50° C.) was measured on a PL50 GPCsetup (Polymer Laboratories, Amherst, Mass.) with a PL Gel 5 μmpre-column and two 10 μm analytical Mixed-D columns (PolymerLaboratories, Amherst, Mass.). NMR spectra were recorded on a BrukerDPX300 spectrometer (Bruker, Madison, Wis.). High resolution massspectra were obtained from a JEOL JMS 700 instrument (JEOL, Peabody,Mass.); Matrix Assisted Laser Desorption and Ionization Time of FlightMass Spectra (MALDI-TOF MS) were measured on a Bruker Daltonics ReflexIII (Bruker, Madison, Wis.).

Monomer Synthesis: Synthesis of 3a

(i) Maleic anhydride (100 g, 1.02 mol) was dissolved in 1 L toluene. 150mL (140.7 g, 2.05 mol) furan was added, and then the solution wasstirred for 3 days according to the literature. The crude product (1)was then filtered, washed with hexanes and dried under vacuum. Acolorless powder was obtained. Spectroscopic data and yield are the sameas reported earlier. (Mantovani, et. al. 2005 J Am. Chem. Soc. 127,2966-2973.) (ii) The same procedure was followed as Lienkamp et. al.with minor modifications. Compound 1 and 2 equivalents of the methanolwere dissolved in DCM and the reaction mixture was stirred overnightafter the addition of 10 mol % DMAP. After the completion of reaction,the solvent was removed by vacuum evaporation at room temperature. Theunreacted alcohol was removed by a dynamic vacuum (5·10⁻² mbar).Crystallization from DCM/hexanes yielded product (2a). Spectroscopicdata and yields matched those reported earlier. (Lienkamp, et al. 2008J. Am. Chem. Soc. 130, 9836-9843.) (iii) 1 equivalent of compound 2a,0.9 equivalents of 1, 3-Di-Boc-2-(2-hydroxyethyl)guanidine and 10 mol %of DMAP were dissolved in DCM, then the solution was cooled to 0° C. and1 equivalent of EDC was added, and the solution was stirred over night.The reaction mixture was diluted in DCM and washed with 10% KHSO₄ (3×25mL) and sat. NaHCO₃ solution (3×25 mL). Next, the organic phase wasdried over Na₂SO₄ and filtered. The volume of solution was reduced byvacuum evaporation, and the product was run through a short aluminacolumn. Vacuum evaporation of the solvent yielded the pure product 3a.The yield ranged from ˜70%.

Synthesis of 3b

Compound 1 and 1.9 equivalents of the respective alcohol were dissolvedin DCM, and the reaction mixture was stirred overnight after theaddition of 10 mol % DMAP. After all components were dissolved, thesolution was cooled down to 0° C. in an ice bath, and 1 equivalent ofEDC was added. The solution was stirred over night. The reaction mixturewas diluted in DCM and washed with 10% KHSO₄ (3×25 mL) and sat. NaHCO₃solution (3×25 mL). Next the organic phase was dried over Na₂SO₄ andfiltered. The volume of solution was reduced by vacuum evaporation, andthe product was run through a short alumina column. Vacuum evaporationof the solvent yielded the pure product 3b. The yield ranged from ˜80%.

3a: R=methyl

colorless solid. ¹H-NMR (300 MHz, CDCl₃): δ=11.50 (1H, s), 8.55 (1H, s),6.46 (2H, s), 5.3 (2H, d, J=6.0 Hz), 4.25 (2H, m), 3.72 (5H, m), 2.84(2H, s), 1.49 (18H, s). ¹³C-NMR (75 MHz, CDCl₃): δ=171.7, 171.5, 163.4,156.3, 153.1, 136.6, 83.2, 80.7, 80.6, 79.4, 63.5, 52.4, 47.1, 46.6,39.4, 28.3, 28.1. HR-MS (FAB): calc. 483.22, found 484.23.

3b

R=1,3-Di-Boc-2-ethyl guanidine: colorless solid. ¹H-NMR (300 MHz,CDCl₃): δ=11.50 (2H, s), 8.55 (2H, s), 6.42 (2H, s), 5.3 (2H, s), 4.26(4H, m), 3.71 (4H, m), 2.85 (2H, s), 1.49 (36H, s). ¹³C-NMR (75 MHz,CDCl₃): δ=171.3, 163.4, 156.3, 153.1, 136.7, 83.2, 80.9, 63.6, 46.7,39.4, 28.3, 28.2, HR-MS (FAB): calc. 754.37, found 755.3.

Synthesis of NBD-Labeled Compound 4

NBD-ethyl amine molecule was synthesized as described earlier⁵⁴. A knownamount of compound 4 and NBD-ethylenediamine were dissolved in 1 mLanhydrous DMF; then DIPEA (1 eq.) was added and stirred overnight in thedark. DMF was removed (via dynamic vacuum). Product was further purifiedby filtering through a silica column.

NBD-Labeled 4

orange colored solid. ¹H-NMR (300 MHz, DMSO-d6): δ=8.00 (1H, m), 7.68(1H, d, J=10.2 Hz), 6.11 (2H, s), 5.91 (1H, d, J=10.2 Hz), 3.87 (1H, m),3.47 (2H, d, J=6.0 Hz), 2.79 (2H, d, J=16.5 Hz), 2.03 (1H, m), 1.76 (1H,m), 1.66 (1H, d, J=7.8 Hz), 1.14 (2H, m).

Polymer Synthesis

Known amounts of monomer 4 and G3-catalyst were dissolved in DCM indifferent shlenk tubes, and each was subjected to three freeze-thawcycles. Then, the monomer was added in one shot to the vigorouslystirring catalyst solution at 0° C. After 20 min, second monomer 3a or3b was added into the reaction mixture at room temperature and stirredfor 90 min. Then, living polymer chain was end-capped by an excess ofethylvinyl ether. After stirring for 120 min, the solution was addeddrop-wise to 50 mL of stirring pentane to precipitate the polymer. Thepentane solution was stirred for an additional 15 min and left standingunperturbed for an hour at 0° C. Then, the precipitate was collected bya fine sinter funnel to yield products 5a-b.

TABLE 1 Molecular Weight Characterization by GPC N repeat Mn by PolymerMonomer 3 units GPC PDI M9  methyl- 9 4600 1.06 guanidine M12 methyl- 126100 1.06 guanidine M18 methyl- 18 8900 1.09 guanidine D5  di-guanidine5 4000 1.06 D9  di-guanidine 9 7000 1.08 D12 di-guanidine 12 9300 1.1D18 di-guanidine 18 14000 1.09

5a: R=Methyl. (M9)

¹H NMR (300 MHz, DMSO-d₆): δ=11.49 (1H, br), 8.42 (1H, br), 7.41 (0.5H,br), 5.80 (trans) and 5.58 (cis) (2H total, br), 4.90 (trans) and 4.56(cis) (2H total, br), 4.10 (2H, br), 3.52 (3H, br), 3.20 (2H, br), 3.04(2H, br), 2.80 (0.4H, br), 2.35 (0.2H, br), 2.29 (0.2H, br), 1.45 (9H,s), 1.37 (9H, s)

5b: R=1,3-Di-Boc-2-ethyl guanidine (D5)

¹H NMR (300 MHz, DMSO-d₆): δ=11.46 (2H, br), 8.38 (2H, br), 7.31 (1H,br), 5.80 (trans) and 5.56 (cis) (2H total, br), 4.96 (trans) and 4.58(cis) (2H total, br), 4.09 (4H, br), 3.49 (4H, br), 3.17 (2H, br), 2.77(0.8H, br), 2.29 (0.4H, br), 2.24 (0.4H, br), 1.41 (18H, s), 1.34 (18H,s)

Polymers 5a-b and TFA salt of2-(7-nitrobenz-2-oxa-1,3diazole)-ethylenediamine (NBD-ethylenediamine)(1:1.5 ratio) were dissolved in 1 mL anhydrous DMF; then DIPEA (1 eq.)was added and stirred overnight in the dark. (Taliani, et. al. 2007 JMed. Chem. 50, 404-407.) 3 mL RO water was added to the reaction flask,filled into a porous membrane and was dialyzed against RO water. Thenthe polymers were freeze-dried. For further purification, the resultingpolymer was dissolved in 1 mL of THF and filtered through a short silicacolumn. Polymers 6a-b were obtained after complete evaporation of thesolvent.

6a: R=Methyl. (M9)¹H NMR (300 MHz, DMSO-d₆): δ=11.49 (1H, br), 8.42 (1H,br), 7.40 (0.5H, br), 5.80 (trans) and 5.58 (cis) (2H total, br), 4.90(cis) and 4.56 (trans) (2H total, br), 4.10 (2H, br), 3.52 (3H, br),3.20 (2H, br), 3.04 (2H, br), 2.35 (0.2H, br), 2.29 (0.2H, br), 1.45(9H, s), 1.37 (9H, s).

6b: R=1,3-Di-Boc-2-ethyl guanidine. (D5)¹H NMR (300 MHz, DMSO-d₆):δ=11.50 (2H, br), 8.41 (2H, br), 7.31 (1H, br), 5.83 (trans) and 5.54(cis) (2H total, br), 4.99 (cis) and 4.61 (trans) (2H total, br), 4.16(4H, br), 3.52 (4H, br), 3.15 (2H, br), 2.34 (0.4H, br), 2.27 (0.4H,br), 1.44 (18H, s), 1.37 (18H, s)

Polymers 6a-b were dissolved in 4 mL DCM and 4 mL TFA for deprotection.After stirring overnight, the excess acid was removed by azeotropicdistillation with methanol. After complete evaporation of the acid,samples were dissolved in methanol:water (1:20) and dialyzed against ROwater until the conductivity of water was ˜0.1 μS. Then deprotectedpolymers were recovered by lyophilization. The final deprotectedpolymers 7a-b were protected from moisture and stored at 4° C.

7a: R=Methyl (M9)¹H NMR (300 MHz, DMSO-d₆): δ=7.84 (1H, br), 7.34 (4H,br), 5.81 (trans) and 5.63 (cis) (2H total, br), 4.92 (cis) and 4.55(trans) (2H total, br), 4.05 (2H, br), 3.58 (3H, br), 3.25 (2H, br).

7b: R=ethyl guanidinium. (D5)¹H NMR (300 MHz, DMSO-d₆): δ=7.99 (2H, br),7.43 (8H, br), 5.83 (trans) and 5.60 (cis) (2H total, br), 4.96 (cis)and 4.62 (trans) (2H total, br), 4.05 (4H, br), 3.27 (2H, br), 2.20(0.4H, br), 2.11 (0.4H, br).

Synthesis of Polymer 8

exo,exo-7-oxa-5-norbornene-2,3-dicarboxylic anhydride was synthesizedaccording to the procedure published previously. (Lienkamp, et al. 2009J. Polym. Sci. Part A: Polym. Chem. 47, 1266-1273.) Polymer 8 wassynthesized with the same procedure as described above.

8:

¹H NMR (300 MHz, DMSO-d₆): δ=12.67 (2H, br), 8.53 (0.1H, br), 7.33 (1H,br), 6.43 (0.1H, br), 5.77 (trans) and 5.52 (cis) (2H total, br), 5.30(trans) and 5.25 (cis) (0.2H total, br), 5.15 (cis) and 5.10 (trans)(0.2H total, br), 4.92 (cis) and 4.51 (trans) (2H total, br), 2.99 (2H,br), 2.72 (0.1H, br), 2.33 (0.1H, br), 2.26 (0.2H, br), 1.22 (0.2H, br).

Cell Cultures

Human Embryonic Kidney (HEK293T) cells were cultured in Iscove'sModified Dulbecco's Medium (IMDM), supplemented with 10% (v/v) fetalbovine serum (FBS), 0.05 mg/ml gentamicin, 10 mM NIE aminoacids, andsodium pyruvate. Chinese Hamster Ovary (CHO) cells were cultivated innutrient mixture F-12 (Ham's F-12) with 10% (v/v) FBS. Jurkat cells(human T cell line, E6.1) were grown in RPMI 1640 (+glutamaxI),supplemented with 10% (v/v) FCS.

Cellular Uptake Experiments with Fluorescence Activated Cell Sorter(FACS)

A known amount of NBD-labeled polymers were dissolved in PBS (pH=7.2)and filtered with a sterile 0.22 μM syringe filter. On the day of theexperiment, cells were counted, centrifuged and resuspended in acomplete growth medium to obtain 1×10⁶ cells/ml for HEK293T and Jurkat Tcells, 1×10⁵ cells/ml for CHO cells. NBD-labeled molecules wereincubated with cells in the same medium either at 37° C. or 4° C. (finalvolume was 1 mL) for 30 min. Then cells were placed in eppendorf tubes,centrifuged and washed 2 times with ice-cold CBE (PBS containing 0.2%BSA and 1 mM EDTA). The cells were then resuspended in 500 μL CBE andanalyzed by fluorescence activated cell sorter-FACS (BD LSR II). Cellassociated fluorophores were excited at 488 nm, and fluorescence wasmeasured at 530 nm. The fluorescence signal was collected for 10,000cells, and the cells exhibiting a normal morphology were used to obtaina histogram of fluorescence intensity per cell. The calculated mean ofthe distribution represented the amount of cell associated molecules.

For the quenching experiments, after the last washing step, cells weretreated with freshly prepared 5 μM sodium dithionite solution (in 1MTRIS pH=10) for 5 min then washed and resuspended in 0.5 mL ice-cold CBEfor FACS analysis.

The fluorescence obtained with dithionite treatment was named asinternalized and the fluorescence obtained without dithionite treatmentwas named as total cell associated. The percent cellular uptake which isreported in the main text is the ratio of internalized fluorescence tototal fluorescence.

Percent Cellular Uptake=[(Internalized fluorescence)/(Totalfluorescence)]*100

7-AAD Viability Test

Cells were treated with the polymers at 37° C. in complete growth mediafor 1 hour as described above. After the last washing step, 20 μL of7-AAD (7-amino-actinomycin D) viability dye was added to the cells in500 μL CBE buffer, incubated on ice and in dark at least for 20 min andimmediately analyzed by FACS.

Confocal Microscopy

Cells were seeded in NUNC 2 chambers to reach 50% confluence 1 day afterseeding. On the day of the experiment, before incubating cells with thecompounds, old media was removed and pre-heated fresh medium was added.After 1 hour of incubation with NBD-labeled polymers, cells were washedwith HBSS buffer and then incubated with lysotracker red-99 for 4 min inHBSS. After 4 min incubation, cells were washed 2 times and placed intoHBSS buffer for imaging. Cells were observed with an inverted LSM510laser scanning confocal microscope (Carl Zeiss) and 40× oil immersionobjective.

Aromatic Functionality in Synthetic Mimics

A new series of PDTMs were designed to determine if aromaticfunctionality provides better transduction efficiency than aliphaticones, at the same relative hydrophobicity. Given the importance ofaromatic amino acids in membrane proteins and their interactions withthe bilayer, it was proposed that aromatic side chains would make betteractivators, given equal relative hydrophobicity. Using reverse-phaseHPLC to determine side chain hydrophobicity and EC₅₀ values in a classictransduction experiment, it was possible to differentiate between sidechain hydrophobicity and aromaticity.

As shown in FIG. 38, a series of new PTDM polymers were prepared viaring opening metathesis polymerization. Monomers were prepared viaMitsunobu coupling reactions. Five different alcohols were used toprepare these monomers including 1-octanol (Oc), 2-cyclohexylethanol(Cy), 2-phenylethanol (Ph), 2-(1-napthyl)ethanol (Np), and1-pyrenylmthanol (Py). Random copolymers (50:50 mol %) were preparedwith degrees of polymerization between 30-35 and M_(n)=10.6-16.6 kDa forthe Boc-protected polymers. Gel-permeation chromatography gave monomodalsignals and narrow polydispersity indices (1.05-1.08). The Boc protectedpolymers were deprotected and their transduction activities werestudied.

Reverse-phase HPLC was performed on each non-polar monomer. Using aC8-column in 100% acetonitrile (isocratic), the chromatograms of allfive nonpolar monomers were obtained as shown in FIG. 2. Since pyrenehas been commonly used as an activator of polyarginine its retentiontime (R_(t)) was of particular interest. (Takeuchi, et al. 2006 ACSChem. Biol. 1, 299; Sakai, et al. 2003 J. Am. Chem. Soc. 125, 14348;Sakai, et al. 2006 Soft Matter 2, 636; Sakai, et al. 2005 Chembiochem 6,114; Nishihara, et al. 2005 Org. Biomol. Chem. 3, 1659; Perret, et al.2005 J. Am. Chem. Soc. 127, 1114.) Here, its R_(t) was 4.57 minuteswhile the eight carbon-containing aliphatic monomers yielded similarR_(t)s of 4.55 (Cy), and 4.50 (Oc). As a result, these three monomershave similar relative hydrophobicities. In contrast, the other twoaromatic monomers, Np and Ph are less hydrophobic with R_(t)s of 4.27and 4.15 minutes, respectively. This series of monomers spans a range ofrelative hydrophobicities and therefore enables the deconvolution ofhydrophobicity and aromaticity in transduction activity.

Transport activities for these novel PTDMs were determined using thestandard biophysical assay well documented in the CPP literature.(Hennig, et al. 2008 J Am. Chem. Soc. 130, 10338.) Specifically,5(6)-carboxyfluorescein (CF) was used as a fluorescent probe in egg yolkphosphatidylcholine large unilamellar vesicles (EYPC-LUVs). The activityof these transporters increased with increasing polymer concentration ata constant vesicle concentration as detected by CF emission intensity,yielding plots of fluorescence intensity versus polymer concentration(FIG. 42, FIG. 43). Fitting the Hill equation [Y ∝(c/EC₅₀)^(n)] to thisdata for each individual polymer revealed a nonlinear dependence of thefractional fluorescence intensity, Y, on the polymer concentration, c,which is classical behavior demonstrated by CPPs. (Sakai, et al. 2003 JAm. Chem. Soc. 125, 14348; Sakai, et al. 2006 Soft Matter 2, 636; Sakai,et al. 2005 Chembiochem 6, 114; Hennig, et al. 2008 J Am. Chem. Soc.130, 10338; Nishihara, et al. 2005 Org. Biomol. Chem., 3, 1659; Perret,et al. 2005 J Am. Chem. Soc. 127, 1114.) This analysis gave Y_(max)(maximal CF release relative to complete release by Triton X-100), EC₅₀(effective polymer concentration needed to reach Y_(max)/2), and theHill coefficient n (see Table 2). For direct comparison it is worthmentioning that the CPP polyarginine was inactive under theseconditions; a known fact since polyarginine needs counterions foractivation.

FIG. 40a is a plot of 1/EC₅₀ vs. 1/R_(t) for GOc, GCy, GPy and GPh. Thedata was plotted in this way to give the most efficient transporter thehighest value as it relates to effective concentration. Since lower EC₅₀values are said to be more active, 1/EC₅₀ directly provides the largestvalue for the best transporter. Similarly, it would be ideal to limitthe hydrophobicity of the transporters while maintaining efficienttransport activity, thus 1/R_(t) was plotted since the retention time islarger for more hydrophobic monomers. FIG. 40a shows that while GOc,GCy, and GPy have similar 1/R_(t) values, GPy is a more effectivetransporter (higher 1/EC₅₀). In fact, it is approximately 1.5 to 2.0times more active than GOc or GCy, despite the similar relativehydrophobicities of their corresponding nonpolar monomers. This activitydifference is similar to that previously reported for pyrene (EC₅₀, 6.7μM and 9.3 μM) vs. alkyl activators (EC₅₀, 16 μM and 19 μM), suggestingaromatic functionality may indeed have a special role in PTD(M)transduction.

Further support for this hypothesis comes from comparing the values(EC₅₀ and hydrophobicity) of GPh to the others in FIG. 3a . GPh is theleast hydrophobic (larger 1/R_(t)) yet it is the most active (higher1/EC₅₀). This is consistent with phenylalanine's unique ability topartition at the membrane interface and in the membrane core. (Sengupta,et al. 2008 Biochim. Biophys. Acta. 1778, 2234.) FIG. 40b shows the Hillplots for GOc, GCy, and GPh which yields their respective EC₅₀ values of11.4±2.8, 9.7±0.9, and 4.3±0.1 nM. This comparison is particularlyinteresting since all three non-polar monomers contain eight totalcarbons. In addition, both GPh and GCy contain cyclic rings and, infact, represent the closest possible structural analogues. While thearomatic group was expected to be less hydrophobic, it clearlydemonstrates that transduction activity is not solely dominated byhydrophocity; but rather that aromaticity plays a crucial role.(Talhout, et al. 2004 Org. Biomol. Chem. 2, 3071.) It also shows thatthe large pyrene-ring is not essential and that smaller, moreprotein-like aromatic groups, can effectively promote transduction inthese PDTMs.

To further examine the role of aromatic size on transduction activityfor this system, copolymers containing naphthyl were prepared. The 50:50copolymer provided a similar EC₅₀ value (3.8±0.6 nM, see FIG. 41 andTable 2) to the other aromatic-containing polymers. Given the similarityin values among all three aromatic-containing polymers, the molarcontent of napthyl was lower to understand whether or not a ‘threshold’of aromatic content was needed for activity. As FIG. 41 shows, theactivity of GNp decreased with decreasing molar content of napthyl,suggesting that no threshold was present. This data indicates that whenmore napthyl is present in the polymer it is more effective attransduction, although there is likely an upper limit, at least due tosolubility of the polymer.

Table 2 summarizes the Hill parameters for these polymers and shows thatthey all have similar Y_(max) values and Hill coefficients, n, around 2,suggesting poor cooperativity. This supports transduction and norequirement for multi-chain structures being involved in the transportactivity. At the same time, this assumes the mechanism of action inthese experiments is transduction and not some type of general poreformation. Previously the activity of the PTDMs was compared againstEYPC/EYPG vesicles containing either CF or calcein. Calcein loadedvesicles are routinely used to demonstrate pore-formation induced byantimicrobial peptides and their synthetic mimics.¹⁶ Nonlinear increasesin the fractional fluorescence from EYPC/EYPG⊃CF vesicles as a functionof concentration were observed while no fluorescence increase wasobserved for EYPC/EYPG⊃Calcein vesicles. These experiments stronglysupported the hypothesis that these class of PTDMs exhibit transductionactivity. As a result, transduction is the most likely and expectedmechanism here.

TABLE 2 EC₅₀, Y_(max), and Hill coefficient of the copolymerstransduction activity Polymer EC₅₀ (nM) Y_(max) n GOc (50:50) 11.4 ± 2.80.80 ± 0.02 1.7 ± 0.05 GCy (50:50)  9.7 ± 0.9 0.80 ± 0.03 2.6 ± 1.0  GPh(50:50)  4.3 ± 0.1 0.96 ± 0.01 1.1 ± 0.1  GNp (50:50)  3.8 ± 0.6 0.84 ±0.04 1.4 ± 0.2  GNp (80:20)  7.8 ± 1.8 0.88 ± 0.02 1.2 ± 0.2  GNp(96:04)   73 ± 0.9 0.91 ± 0.03 0.9 ± 0.1  GPy (50:50)  6.1 ± 0.2 0.81 ±0.01 2.8 ± 0.3 

The molar ratios between guanidino repeat units and the hydrophobicrepeat units are reported in the parenthesis. Y_(max) (maximal CFrelease relative to complete release by Triton X-100); EC₅₀ (effectivepolymer concentration needed to reach Y_(max)/2); n, Hill coefficient.Each data point was collected in three independent experiments.

In order to compare ‘activators’ of varying EC₅₀s and total fractionaltransport activity, activator efficiency, E, was calculated based on theexponential relationship between Y_(max) and EC₅₀. (Nishihara, et al.2005 Org. Biomol. Chem. 3, 1659.) The same arbitrary scaling factorpreviously was used to calibrate E between 0 and 10^(5a) was also usedhere to determine E values for these covalently activated PTDMs (Table3). For GPh, E was found to be 25, or 2.5 times larger than the highlyactive fullerene analog and 5 times better than pyrene butyrate. Thesecovalent PDTMs have both low EC₅₀ and high Y_(max) values, featurespreviously suggested for the perfect activator. (Nishihara, et al. 2005Org. Biomol. Chem. 3, 1659.) This is markedly different from thesupramolecular activators in which more potent activators (lowest EC₅₀s)also had low Y_(max) values. The fact that these covalently activatedPTDMs are more effective than the supramolecular analogs (pR-activator)is not necessarily surprising since covalent attachment eliminates thebinding equilibrium between pR and the activator. The best activatorsmost likely also have solubility limitations since they aresignificantly hydrophobic. At the same time, the ability to design PTDMsthat are significantly more active than classical CPPs is extremelyencouraging.

TABLE S1 Polymer EC₅₀ (low M_(n)) (μM) Y_(max) n G1  20.0 ± 0.9   0.85 ±0.03 1.2 ± 0.1 G2  2.4 ± 0.2  1.0 1.0 ± 0.3 G3  0.3 ± 0.04 0.96 ± 0.012.5 ± 0.6 G4  0.2 ± 0.06 0.95 ± 0.02 2.5 ± 0.2 G5  0.6 ± 0.03 0.98 ±0.01 1.8 ± 0.4 G9  5.4 ± 0.4  0.60 ± 0.03 1.7 ± 0.3 G12 6.8 ± 0.5  0.51± 0.03 3.5 ± 0.3

Using HPLC to determine the relative hydrophobicity of various sidechains, it was possible to demonstrate the improved transport activityof aromatic functionality. This provides guidance for building moleculesthat more favorably interact with the membrane while reducing theoverall hydrophobicity. Understanding the broader goals of howmacromolecules (synthetic or natural) interact with the biologicalmembrane is critically important. At the same time, learning to programsynthetic polymers with natural protein-like activity remains anincredibly important task of modern macromolecular chemistry. Manyfundamental questions remain but these new synthetic PDTMs appear to beuseful tools for studying macromolecular-membrane interactions.

Monomers of Copolymers

These monomers were synthesized following reported procedure with minormodifications. (Gabriel, et al. 2009 Chem. Eur. J 15, 433-439)

Oxanorbornene Imide.

10.0 g (103 mmol) of maleimide was dissolved in 100 mL of ethyl acetate.7.7 g (8.2 mL, 113.0 mmol) of furan were added and the resultingsolution was vigorously stirred at 90° C. for 3 h to obtain productoxanorbornene imide as a white precipitate. Product was then filtered,washed with excess diethyl ether, and dried under vacuum overnight. 100%exo isomer was obtained as a colorless powder. Spectroscopic datamatched the previously reported ones (Yield=75%). (Kim, et al. 1997Journal of Applied Polymer Science 64, 2605-2612.)

DiBoc-Protected Guanidine Monomer (G)

To a round-bottom flask charged with oxanorbornene imide (1.0 g, 6.0mmol), 1,3-Di-Boc-2-(2-hydroxyethyl)guanidine (2.12 g, 7.0 mmol) andtriphenylphosphine (1.6 g, 6.0 mmol), THF (30 mL) were added. Thesolution mixture was then immersed in an ice bath, and diisopropylazodicarboxylate (DIAD) (1.2 mL, 6.0 mmol) was added dropwise. After theaddition of DIAD, the ice bath was removed and the reaction was allowedto stir at room temperature for 24 h. The solvent was removed underreduced pressure, and the product was crystallized from diethyl etherand was purified by column chromatography (silica gel, 96:4dichloromethane/acetone) in 70% yield. NMR characterization of thismonomer is reported below.

DiBoc-Protected Guanidine Monomer (G)

¹H NMR (300 MHz, CDCl₃): δ=11.45 (1H, s), 8.41 (1H, s), 6.51 (2H, s),5.26 (2H, s), 3.68 (2H, m), 3.60 (2H, m), 2.86 (2H, s), 1.50 (9H, s),1.47 (9H, s). ¹³C-NMR (75 MHz, DMSO-d₆): δ=176.3, 156.6, 153.0, 136.5,83.3, 80.9, 47.6, 39.0, 38.4, 28.3, 28.1. HR-MS (FAB): calc. 451.49,found 451.22.

Scheme 6. The synthetic scheme of hydrophobic monomers

R Monomer

Oc

Cy

Ph

Np

Py

Hydrophobic Monomers

Oxanorbornene imide (1.0 g, 6.0 mmol, 1 eq.), the appropriate alcohol(1.16 eq.) and triphenylphosphine (1.6 g, 6.0 mmol), dry THF (35 mL)were added to a round-bottom flask, purged with nitrogen. The reactionmixture was stirred and the cooled to 0° C. in an ice bath anddiisopropyl azodicarboxylate (DIAD) (1.2 mL, 6.0 mmol) was addeddropwise. After the addition of DIAD the ice bath was removed and thesolution was allowed to stir for 16 h. The solvent was removed underreduced pressure. To remove by-products, the solid was dissolved inminimum amount of toluene. The precipitating solid was filtered and thesolvent in the mother liquor removed under reduced pressure. The oil wasdissolved in minimum amount of diethylether. The precipitating solid wasdissolved in minimum amount of dichloromethane and purified by columnchromatography using a dichloromethane/ethyl acetate gradient in 70-80%yield. NMR characterization of monomers follows below.

Octyl Monomer (Oc).

¹H NMR (300 MHz, CDCl₃): δ=6.48 (2H, s), 5.22 (2H, S), 3.42 (2H, t,J=7.3 Hz), 2.80 (2H, s), 1.51 (dq, J=6.8 Hz, 8.3 Hz, 2H), 1.22 (10H,br), 0.85 (3H, t, J=6.0 Hz). ¹³C-NMR (75 MHz, CDCl₃): δ=176.2, 136.4,80.8, 62.8, 47.2, 38.9, 31.6, 29.0, 27.5, 26.5, 22.5, 14.0. HR-MS (FAB):calc. 277.17, found 278.17.

Cyclohexyl Monomer (Cy).

¹H NMR (300 MHz, CDCl₃): δ=6.49 (2H, s), 5.24 (2H, s), 3.46 (2H, t,J=7.6 Hz), 2.81 (2H, s), 1.64 (5H, m), 1.41 (2H, q, J=7.5 Hz), 1.20 (4H,m), 0.90 (2H, m). ¹³C-NMR (75 MHz, CDCl₃): δ=176.3, 136.6, 80.9, 47.4,37.1, 35.4, 34.9, 32.9, 26.5, 26.2. HR-MS (FAB): calc. 276.35, found276.16.

Phenyl Monomer (Ph). ¹H NMR (300 MHz, Acetone-d₆): δ=7.26 (5H, m), 6.59(2H, s), 5.14 (2H, s), 3.62 (2H, t, J=7.7 Hz), 2.91 (2H, s), 2.79 (2H,t, J=6.9 Hz). 1³C-NMR (75 MHz, CDCl₃): δ=176.0, 137.8, 136.6, 128.9,128.5, 126.6, 80.9, 47.4, 40.2, 33.7. HR-MS (FAB): calc. 270.30, found270.11.

Naphthyl Monomer (Np).

¹H NMR (300 MHz, Acetone-d₆): δ=8.30 (1H, d, J=8.1 Hz), 7.94 (1H, d,J=7.8 Hz), 7.82 (1H, dd, J=7.2 Hz, 2.1 Hz), 7.65-7.52 (2H, m), 7.47-7.40(2H, m), 6.60 (2H, s), 5.19 (2H, s), 3.74 (2H, td, J=4.1 Hz, 7.5 Hz),3.27 (2H, td, J=3.6 Hz, 6.8 Hz), 2.95 (2H, s). ¹³C-NMR (75 MHz, CDCl₃):δ=176.1, 136.6, 134.0, 133.8, 132.0, 128.8, 127.6, 127.1, 126.4, 125.7,125.5, 123.7, 80.9, 47.5, 39.7, 31.2. HR-MS (FAB): calc. 319.35, found319.12.

Pyrene Monomer (Py). ¹H NMR (300 MHz, DMSO-d6, poor solubility):δ=8.48−7.87 (9H, m), 6.58 (2H, s), 5.31 (2H, s), 5.22 (2H, s), 3.08 (2H,br). HR-MS (EI): calc. 379.40, found 379.10.

Reverse-Phase HPLC Analysis. Solutions of Oc, Cy, Ph, Np, and Pymonomers (in acetonitrile) were eluted off of the column (Agilent ZorbaxC8 column, 4.6 mm×150 mm) under isocratic condition with 100%acetonitrile; flow rate was 0.5 mL/min and absorbance at 212 nm wasmonitored in Waters 2695 Separation Module HPLC system equipped with aWaters 2996 photodiode array.

Scheme 7. The synthetic scheme of copolymers.

R Polymer

GOc

GCy

GPh

GNp

GPy

The 50:50 random copolymers were prepared following the procedure byGabriel et. al. Monomers were copolymerixed by ring-opening metathesispolymerization (ROMP) using Grubbs' 3^(rd) generation catalyst, G3,Dichloro-di(3-bromopyridino)-N,N′-Dimesitylenoimidazolino-Ru═CHPh. Thepolymerization entailed adding to a schlenk tube the appropriatemonomers (ca. 100 mg total) and in another schlenk tube the G3 catalyst.The schlenk tubes were purged with N₂ for 5 min, then 1 mL dry CH₂Cl₂was injected into both tubes followed by three freeze thaw cycles.Afterwards the monomer solution was added into the catalyst solution viasyringe all at a time. The N₂ line was removed and the clear, brownsolution was stirred at 30° C. for 30 min after which 0.4 mL ethyl vinylether was injected to terminate the polymerization. After stirring for15 min the solution was added dropwise to 300 mL of stirring pentane toprecipitate the polymer. The pentane solution was stirred an additional30 min and left standing undisturbed for an hour. The precipitate wasthen collected by a fine sintered funnel and then dried by vacuum for 8h. GNp 80:20 copolymers, and GNp 96:4 copolymers were prepared followingthe same general procedure reported above only by changing theappropriate monomer ratios. NMR and GPC characterization of all theBoc-protected copolymers follows below.

The Boc-protected polymers were deprotected by stirring 100 mg in 4 mLof 1:1 TFA:CH₂Cl₂ for 6 h. The solution was dried under N₂ to an oil andthe residual TFA was removed by washing the oil in CH₂Cl₂/MeOH andevaporating the solvent by rotary evaporator. After three more MeOH washand the solvent evaporation, the resulting solid was placed under vacuumfor 2 h. Finally, the solid was fully dissolved in 4 mL 1:1 MeOH:H₂O andfreeze-dried for 48 h to give an eggshell colored soft solid. Finaldeprotected polymers were stored at −20° C. NMR characterization of thedeprotected copolymers follows below. After Boc-deprotectionand and MeOHwash, GNp and GPy copolymers were precipitated in cold ether. Theprecipitate was then collected by a fine sintered funnel and the whitesolid was dried by vacuum.

Boc-Protected GOc.

¹H NMR (300 MHz, CDCl₃): δ=11.42 (1H, br), 8.48 (1H, br), 6.06 (2H, br),5.76 (2H, br), 5.02 (2H, br), 4.47 (2H, br), 3.67 (4H, br), 3.43-3.32(6H, br, m), 1.46 (18H, s), 1.25 (12H, br), 0.85 (3H, br). cis:transratio=43:56; M=14.9 kDa, M_(w)/M_(n)=1.08.

GOc.

(300 MHz, DMSO-d₆): δ=7.72 (2H, br, exchanged with D₂O), 7.29 (4H, br,exchanged with D₂O), 5.94 (2H, br), 5.72 (2H, br), 4.86 (2H, br), 4.41(2H, br), 1.44 (2H, br), 1.21 (9H, br), 0.82 (3H, br).

Boc-Protected GCy.

¹H NMR (300 MHz, CDCl₃): δ=11.44 (1H, br), 8.50 (1H, br), 6.06 (2H, br),5.76 (2H, br), 4.99 (2H, br), 4.47 (2H, br), 3.68 (4H, br), 3.47-3.31(6H, br), 1.71-1.66 (5H, m, br) 1.47 (18H, s), 1.18 (5H, br), 0.90 (3H,br). cis:trans ratio=46:54; M_(n)=13.0 kDa, M_(w)/ML=1.05.

GCy.

¹H NMR (300 MHz, CD₃OD): δ=6.08 (2H, br), 5.84 (2H, br), 5.02 (2H, br),4.52 (2H, br), 3.69 (2H, br), 3.46 (8H, br), 1.76 (5H, br), 1.45 (2H,br), 1.25 (4H, br), 0.96 (2H, br).

Boc-Protected GPh.

¹H NMR (300 MHz, CDCl₃): δ=11.44 (1H, br, m), 8.50 (1H, br), 7.29-7.18(5H, br, m, some overlaping with CHCl₃ peak; clearly visible, 7.29-7.23,when spectra recorded in Acetone-d6), 5.99 (2H, br, t, J=20.8 Hz), 5.73(2H, br), 5.06-4.83 (2H, br, m), 4.47 (1H, br), 4.09 (1H, br), 3.68 (6H,br), 3.34-3.18 (4H, br, m), 2.90 (2H, br), 1.49 (9H, br), 1.47 (9H, br),cis:trans ratio=47:53; M_(n)=10.6 kDa, M_(w)/M_(n)=1.05.

GPh.

¹H NMR (300 MHz, CD₃OD): δ=7.20 (5H, br), 6.15-5.79 (4H, br, m), 4.51(2H, br), 3.98 (2H, br), 3.68 (4H, br), 3.44 (4H, br), 2.90 (2H, br).

Boc-Protected GNp.

¹H NMR (300 MHz, CDCl₃): δ=11.45 (1H, br, m), 8.52 (1H, br), 8.14 (1H,br), 7.85-7.29 (6H, br, m), 6.00 (2H, br, t, J=21.7 Hz), 5.77 (2H, br),4.99 (2H, br), 4.49 (1H, br), 4.19 (1H, br), 3.83-3.33 (10H, br, m),1.49 (18H, br). cis:trans ratio=49:51; M_(n)=11.6 kDa, M_(w)/M_(n)=1.05.

GNp.

(300 MHz, DMSO-d₆): δ=8.13 (1H, br), 7.68 (3H, br, m, 1H exchanged withD₂O), 7.31 (8H, 4Hs exchanged with D₂O), 6.04-5.76 (4H, br, m), 4.91(2H, br), 4.49 (1H, br), 4.10 (1H, br), 3.65 (2H, br).

Boc-Protected GNp (80:20).

¹H NMR (300 MHz, CDCl₃): δ=11.45 (1H, br, m), 8.48 (1H, br), 8.12-7.34(2H, br, m), 6.05 (1H, br, m), 5.75 (1H, br), 4.98 (1H, br), 4.50 (1H,br), 4.15-3.31 (7H, br, m), 1.46 (18H, br). cis:trans ratio=49:51;M_(n)=15.8 kDa, M_(w)/M_(n)=1.05.

GNp (80:20).

(300 MHz, DMSO-d₆): δ=8.12-7.27 (10H, br, m, 6Hs exchanged with D₂O),5.94-5.74 (4H, br, m), 4.90 (2H, br), 4.41-4.10 (2H, br), 3.65 (1H, br).

Boc-Protected GNp (96:4).

¹H NMR (300 MHz, CDCl₃): δ=11.45 (1H, br, m), 8.47 (1H, br), 8.12-7.31(1H, br, m), 6.04 (1H, br, m), 5.75 (1H, br), 5.00 (1H, br), 4.45 (1H,br), 3.66-3.30 (7H, br, m), 1.46 (18H, br). cis:trans ratio=46:54;M_(n)=16.6 kDa, M_(w)/M_(n)=1.05.

GNp (96:4).

(300 MHz, DMSO-d₆): δ=7.86−7.33 (10H, br, m, 2Hs exchanged with D₂O),5.93 (2H, br), 5.73 (2H, br), 4.90 (2H, br), 4.40 (2H, br).

Boc-Protected GPy.

¹H NMR (300 MHz, CDCl₃): δ=11.43 (1H, br, m), 8.41 (1H, br), 8.20-7.60(9H, br, m), 5.99 (2H, br), 5.67 (2H, br), 4.92 (2H, br), 4.38 (2H, br),3.55-3.01 (6H, br, m), 1.44 (18H, br). cis:trans ratio=50:50; M_(n)=11.1kDa, M_(w)/M_(n)=1.07.

GNp.

(300 MHz, DMSO-d₆): δ=8.42-7.07 (12H, br, m), 5.93 (2H, br), 5.70 (2H,br), 5.21-4.81 (4H, br), 4.41 (2H, br).

Preparation of Vesicles Preparation of EYPC-LUVs⊃CF

A thin lipid film was prepared by evaporating a solution of 25 mg EYPCin 2 mL CHCl₃ on a rotary evaporator (40° C.) and then in vacuumovernight. After hydration (˜1 h) with 1.0 ml buffer (10 mM Tris, 10 mMNaCl, 50 mM CF, pH 7.5) accompanied by occasional vortex, the resultingsuspension was subjected to 5 freeze-thaw cycles (liquid N₂ to freezeand 40° C. water bath to thaw), and 11 times extruded through apolycarbonate membrane (pore size 100 nm). Extra-vesicular componentswere removed by size exclusion chromatography (Sephadex G-50,Sigma-Aldrich) with 10 mM Tris, 107 mM NaCl, pH 7.5. The resultingvesicle solution was diluted with buffer B to give CF loaded LUVs stocksolution having final lipid concentration of ˜2.5 mM. (Hennig, et al.2008 J. Am. Chem. Soc. 130, 10338-10344.)

Fluorescence Assay and Transporter Activity

Polymer Activity in EYPC-LUVs⊃CF. 20 μL EYPC-LUVs⊃CF were added to 1980μL gently stirred, thermostated buffer (buffer B, 10 mM Tris, 107 mMNaCl, pH 7.5) in a disposable plastic cuvette. The time-dependent changein fluorescence intensity I_(t) (λ_(ex)=492 nm, λ_(em)=517 nm) wasmonitored during the addition of polymer (20 μL stock solution in DMSO)at t=100 s, and addition of 40 μl 1.2% (aq.) triton X-100 at the end ofevery experiment (t=900 s) (FIG. 42). (Hennig, et al. 2008 J Am. Chem.Soc. 130, 10338-10344.) Time courses of I_(t) were normalized tofractional intensities I_(f) using equation S1.

I_(f)═(I_(t)−I₀)/(I_(∞)−I₀)  (S1),

where I₀═I_(t) before polymer addition and I_(∞)═I_(t) after lysis.I_(f) at t=800 s just before lysis was defined as transmembrane activityY. For Hill analysis, Y was plotted against polymer concentration c andfitted to the Hill equation S2 to give effective concentration EC₅₀,Y_(max) and the Hill coefficient n.

Y=Y_(O)+(Y_(max)−Y_(O))/{1+c/EC₅₀)^(n)}  (S2),

Where, Y₀ is Yin absence of polymer, Y_(max) is Y with excess polymer.NOTCH 1-siRNA Delivery to Primary Cells by PTDs

Use of siRNA to study gene functions in T cell lines and primary bloodcells has been limited due to lack of safe and effective deliveryvehicles. There are different tools to introduce siRNA into theintracellular medium of the cells such as electroporation, chitosanbased-polymers, carbon-nanotubes, and protein transduction domains(PTDs). (Jantsch, et al. 2008 J. Immunol. Methods 337, 71-77 (2008);Brahmamdam, et al. 2009 Shock 32, 131-139; Liu, et al. 2007 Angew. Chem.Int. Ed. Engl. 46, 2023-2027; Marshall, et al. 2007 J Immunol. Methods.325, 114-126; Eguchi, et al. 2009 Nat. Biotech. 27, 567-571.) Each ofthese systems offers some benefits but they all have their own concernsregarding cytotoxicity, ease of preparation, and stability. Therefore,there is a great interest in easily prepared agents for efficient siRNAdelivery to hard-to-transfect cells without significant toxicity. Here,two ROMP based PTDMs were prepared and studied. (Trabulo, et al. 2010Pharmaceuticals 3, 961-993; Fonseca, et al. 2009 Adv. Drug Del. Rev. 61,953-964.) There are two different approaches in PTD-based cargodelivery, the first one is attaching cargo to PTD with a covalentlinkage, and the second approach is the formation of stable non-covalentcomplexes between PTD and cargo. (Endoh, et al. 2009 Adv. Drug Del. Rev.61, 704-709.) Especially, in the case of siRNA delivery, second approachis more favored over the first one; in terms of simplicity, deliveryefficiency and cargo stability. (Eguchi, et al. 2009 Trends in Pharm.Sci. 30, 341-345.)

PTDs used in siRNA delivery via non-covalent complexation, generallyhave primary or secondary amphiphilic structures, such as, MPG, CADY,and Pep peptides, to enhance both the stability of complexes andinternalization properties. (Crombez, et al. 2007 Biochem. Soc. Trans.135, 44-46; Crombez, et al. 2009 Mol. Ther. 17, 95-103; Morris, et al.2007 Nucleic Acids Res. 35, e49.) For instance, in the case of Pep-2peptide which is designed for delivery of DNA mimics, an alanine mappingis performed to determine the essential residues required to form stablecomplexes with nucleic acids and to improve their delivery into cells.The results show that aromatic residues are required for both binding ofthe carrier to cargo and the cellular uptake. In addition, it ishighlighted that the cationic residues have more impact oninternalization rather than cargo stabilization. (Morris, et al. 2007Nucleic Acids Res. 35, e49.) Moreover, in the siRNA delivery via PTDs,arginine sequences have been shown to be more effective than theirlysine analogues. (van Rossenberg, et al. 2004 Gene Ther. 11, 457-464.)Two different PTDMs were designed and studied. PTDM-1 is a hydrophilicmolecule which is a mimic of oligoarginine peptide, having guanidiniumfunctionalities along a polyoxanorbonene backbone (FIG. 44a ). Besides,PTDM-2 is a block-copolymer having both hydrophilic, guanidinium andhydrophobic, phenyl moieties on the same backbone (FIG. 44b ) and isinspired by the amphiphilic PTDs.

Initially, to examine the ability of PTDMs to deliver siRNA into JurkatT cells, a FITC-conjugated siRNA molecule was mixed with either PTDM-1or PTDM-2 and resulting complexes were incubated on the cells in eitherserum-free or complete growth medium with 10% serum at 37° C. Afterwashing the cells carefully with heparin solution, they were analyzed bya fluorescence activated cell sorter (FACS) (FIG. 44c, d ). As shown inFIG. 44, both PTDMs are able to deliver siRNA in serum-free medium,single populations and narrow peaks indicate that PTDMs target theentire cell population and all the cells contain almost the same amountof siRNA. PTDM-1 worked much better than PTDM-2 in serum-free media;however, its efficiency was highly inhibited in the presence of serum(FIG. 44c ). In the case of PTDM-2, there was no significant differencebetween serum-free and complete media conditions (FIG. 44d ). Thisdemonstrated the importance of aromatic groups on cargo stabilizationproperties of PTDM-2.

In addition to delivery experiments at 37° C., in order to examine theroute of cell entry, PTDM/siRNA complexes were incubated on the cells at4° C. at which most of the energy-dependent pathways are inhibited.Internalization at 4° C. also highlights the chance of cytosolicdelivery of compounds and their availability to function. When Jurkat Tcells were treated with PTDM-1/FITC-siRNA complexes at 4° C., resultedin no significant delivery of siRNA molecules (FIG. 44e ), howeverPTDM-2 was able to deliver siRNA into the cells even at low temperature(FIG. 44f ). Delivery efficiency of PTDM-2 was lower at 4° C. incomparison to at 37° C., but it can still deliver siRNA molecules to theentire cell population.

Experiments with FITC-tagged siRNA molecules demonstrated that bothPTDMs delivered siRNA into the cells; however, they do not show theavailability of siRNA molecules for gene silencing. To demonstrate theability of PTDMs to deliver functional siRNA molecules, Notch 1 ischosen as a target in Jurkat T cells and human PBMCs. Notch 1 is amember of the Notch transmembrane receptors which are importantregulators of cell-fate decisions and cell survival in many systemsduring embryogenesis and postnatal development, including the immunesystem. (Artavanis-Tsakonas, et al. 1999 Science, 284, 770-776; Osborne,et al. 2007 Nat. Rev. Immunol. 7, 64-75.)

In order to evaluate the function of siRNA molecules, Jurkat T cellswere treated with complexes of siRNA to Notch 1 (siN1) and either PTDM-1or PTDM-2 in serum free media for 4 h, then protein expression level wasanalyzed at 72 h by FACS after staining intracellular domain of Notch 1with fluorescent anti-Notch 1 (FIG. 44g ). Efficient down regulation wasobserved at Notch-1 protein levels in Jurkat T cells treated with bothPTDM-1/siN1 and PTDM-2/siN1 complexes. Both PTDMs performed with thesame efficiency, no significant difference was observed. Furthermore,down regulation efficiencies of PTDM-1 and commercially availablecationic lipids, Lipofectamine 2000, Hifect, and Fugene HD, werecompared in Jurkat T cells (FIG. 44i ). There was no silencing activityin the cells treated with cationic lipid based formulations. On theother hand, a 50% down regulation observed in the cells treated withcomplexes of 80 nM siN1 and 1.6 μM PTDM-1. In addition, the cells werealso treated with a scrambled control siRNA (siCont) and only PTDM-1, toshow that the decrease on Notch 1 protein levels is mediated by Notch 1specific siRNA (FIG. 44h ).

Primary cells are also known as a problematic cell type in terms ofintracellular delivery of macromolecules. Next, the Notch 1 downregulation in human PBMCs by PTDM/siRNA complexes was evaluated. PBMCswere cultured the day before the treatment in order to separate and workwith the T cell-enriched lymphocytes. Initially, suspension part ofPBMCs were treated with PTDM/siRNA complexes in serum free media for 4h, then media was replaced with complete growth media and the cells werestimulated for 72 h to up-regulate Notch 1. At the indicated time point,cells were harvested and intracellular Notch 1 was stained usingfluorescent anti-Notch 1, then analyzed by FACS. Both PTDM-1 and PTDM-2were used to deliver 60 nM siRNA to PBMCs from the same donor and bothPTDMs successfully demonstrated approximately 50% down regulation onNotch 1 protein levels (FIG. 48a, b ). Also, experiments were performedwith scrambled siRNA as a negative control and there is a significantdifference (p<0.01) between siN1 and siCont treated cells which provedthat Notch 1 knockdown is only mediated by siN1. Furthermore, in orderto establish the universality of PTDMs in human PBMCs, deliveryefficiency of PTDM-2 was demonstrated in PBMCs from three differentdonors (FIG. 48c-e ). PTDM-2 showed similar knockdown efficiencies amongdifferent donors with a small variance.

In addition, to examine the stability of PTDM/siRNA complexes and theirability to deliver functional siRNA molecules in the presence of serum,PBMCs were treated with PTDM/siRNA complexes in complete growth mediumwithout further media change. Both PTDM-1 and PTDM-2 performedefficiently in serum-free condition, however in the presence of serum,only PTDM-2 was able to deliver functional siRNA into the cells (FIG.45).

For further analysis, PBMCs were treated with PTDM-2/siRNA complexes incomplete media to knockdown Notch 1. Notch 1 protein levels weremonitored for four days in the cells treated with either PTDM-2/siN1 orPTDM-2/siCont complexes (FIG. 45). At least 50% decrease on Notch 1protein level was observed in the cells treated with the mixture of 100nM siRNA and 3.5 μM PTDM-2 at 24 h, RNAi response showed a slow decayafter 72 h (FIG. 45a, b ). As reported earlier, it is known that Notch 1has an important role on cell-fate decisions. Therefore, to determinewhether down regulation of Notch 1 expression by siRNA has an effect oncell growth of PBMCs, proliferation of cells was also analyzed (FIG. 45c). Down regulation of Notch 1 expression caused significant cell growthinhibition in PBMCs; while untreated and scrambled siRNA treated cellswere in their logarithmic growth phase on the day four. Furthermore, oneof the major limitations in intracellular delivery to primary cells isthe toxicity of delivery tools. In order to investigate the cytotoxiceffect of PTDM-2/siRNA treatment, cells were stained with7-Amino-Actinomycin D (7-AAD) and analyzed by FACS. Neither PTDM-2/siN1nor PTDM-2/siCont treatments affected the cell viability at theconcentrations used (FIG. 45d ).

Knockdown efficiency of PTDM-2/siRNA complexes was also examined atdifferent concentrations of siRNA and among different three donors inthe presence of serum (FIG. 45e-g ). Increasing the siRNA concentrationfrom 100 nM to 150 nM did not affect the efficiency of knockdownsignificantly, and this was consistent among all three donors.

Moreover, Notch 1 has been shown to play an important role in thedevelopment and differentiation of peripheral T cells. Activated CD4+ Tcells can further differentiate into T helper type 1 (T_(H)1) or T_(H)2cells. T_(H)1 and T_(H)2 cells produce specific cytokines during theirterminal maturation. For instance, IFN-γ, tumor necrosis factor is oneof the cytokines which is dominantly expressed by T_(H)1 cells. It hasbeen reported earlier, the expression of T_(H)1 transcription factorT-bet is both necessary and sufficient to drive CD4⁺ T_(H)1differentiation and expression of the cytokine IFN-γ. (Minter, et al.2005 Nat. Immunol. 6, 680-688.) siRNA molecules are great tools toanalyze the function of Notch 1 in primary T cells in a gene-specificmanner which was limited earlier due to lack of efficient and safedelivery tools.

To investigate the effect of Notch 1 expression on CD4⁺T celldifferentiation under T_(H)1 polarization conditions; first PBMCs weretreated with PTDM-2/siN1 or PTDM-2/siCont for 4 hours, then the cellswere polarized with interleukin-12 (IL-12) and anti-interleukin-4 (IL-4mAb), then stimulated with plate bound anti-CD3 and anti-CD28. At 48 h(FIG. 49) or 72 h (FIG. 46) time points, the CD4⁺T cells were identifiedaccording to their reactivity to anti-CD4 monoclonal antibody. In CD4⁺Tcells, Notch 1 and T-bet were also analyzed by anti-Notch 1 andanti-T-bet monoclonal antibodies, respectively. In addition, the cellswere restimulated 6 h with Brefeldin A and stained for IFN-γ which is asignature cytokine of T_(H)1 polarized cells. At the end, cells wereanalyzed by FACS which is a powerful technique to determine both thepercentage of cells undergoing gene-silencing and the amounts of proteindownregulation in the cells of interest. (Chan, et al. 2005 CytometryPart A, 69A, 59-65.)

At 48 h time point, the down regulation of Notch 1 by siN1 inhibited theexpression of T-bet in CD4⁺T cells (FIG. 49d-f ), also inhibited theIFN-γ production compared to untreated and siCont treated cells (FIG.49j-k ). However, at 48 h time point there was a low level of IFN-γproduction in the untreated cells as well (FIG. 49g-i ). Further, thecells were harvested at 72 h time point at which more IFN-γ productionwas observed in control groups (untreated and siCont treated cells) inaccordance with their higher expression of Notch 1 (FIG. 46a-c ) andT-bet (FIG. 46d-f ). IFN-γ production in siN1 treated cells wassignificantly lower than control groups (FIG. 46j-k ).

One of the major limitations to use of RNA interference to study unknowngene functions in primary cells is the inefficient delivery strategies.Here, the system is based on PTDMs generated by ROMP for a safe andefficient delivery of siRNA. PTDM-1, which is a mimic of polyarginine,successfully delivered functional siRNA molecules into hard to transfectcell types, Jurkat T cells and PBMCs, even though it has been reportedthat homopolymers of arginines are not able to deliver siRNA vianon-covalent complexation. (Kim, et al. 2006 Mol. Ther. 14, 343-350;Kumar, et al. 2008 Cell 134, 577-586.) Furthermore, in order to test theeffect of hydrophobicity in addition to arginine functionalities on thecarrier efficiency, PTDM-2 was generated using hydrophobic phenyl andhydrophilic guanidinium functionalities. There was no significantdifference on delivery efficiencies of the PTDM-1 and PTDM-2 in theabsence of serum. On the other hand, PTDM-2 showed a superior efficiencyin the presence of serum where PTDM-1 did not work at all. Thisdemonstrates that the introduction of hydrophobic groups in thestructure of PTDMs improved the stability of complexes and also madethem better candidates for in vivo experiments. Down regulation Notch 1in Jurkat T cells and primary human PBMCs is chosen as a model system.Notch 1 is known to have an important role in T cell development anddifferentiation. Therefore, the role of Notch 1 on cell proliferationand T cell differentiation in human PBMCs was successfully demonstratedvia silencing Notch 1 by novel PTDM-based siRNA delivery system.

Experimental General

Maleic anhydride, furan, 4-dimethyl aminopyridine (DMAP),1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC),methanol, 1,3-Di-Boc-2-(2-hydroxyethyl)guanidine, benzyl alcohol,ethylvinyl ether and trifluoroacetic acid (TFA) were obtained as reagentgrade from Aldrich, Fluka or Acros and used as received.

3^(rd) generation Grubbs catalyst(Dichloro-di(3-bromopyridino)-N,N′-Dimesitylenoimidazolino-Ru═CHPh; G3)was synthesized as described previously by Grubbs et al. (Love, et al.2002 Angew. Chem. Int. Ed. 41, 4035-4037.) The HPLC grade solvents ethylacetate, pentane and hexane were purchased from Aldrich, FisherScientific or Acros and used as received. Tetrahydrofuran (THF) (HPLCgrade, Fisher Scientific) was distilled from sodium/benzophenone undernitrogen. Dichloromethane (DCM) (HPLC grade, Fisher Scientific) wasdistilled from CaH₂ under nitrogen.

Gel permeation chromatography (THF, calibrated with polystyrenestandards, toluene as flow marker, 50° C.) was measured on a PL50 GPCsetup (Polymer Laboratories, Amherst, Mass.) with a PL Gel 5 μmpre-column and two 10 μm analytical Mixed-D columns (PolymerLaboratories, Amherst, Mass.). NMR spectra were recorded on a BrukerDPX300 spectrometer (Bruker, Madison, Wis.). High resolution massspectra were obtained from a JEOL JMS 700 instrument (JEOL, Peabody,Mass.); Matrix Assisted Laser Desorption and Ionization Time of FlightMass Spectra (MALDI-TOF MS) were measured on a Bruker Daltonics ReflexIII (Bruker, Madison, Wis.).

Monomer Synthesis

Synthesis of 2

(i) Maleic anhydride (100 g, 1.02 mol) was dissolved in 1 L toluene, 150mL (140.7 g, 2.05 mol) furan was added, and then the solution wasstirred for 3 days according to the literature. The product (1) was thenfiltered, washed with hexanes and dried under vacuum. A colorless powderwas obtained. Spectroscopic data and yield are the same as reportedearlier. (Mantovani, et. al. 2005 J Am. Chem. Soc. 127, 2966-2973.) (ii)The same procedure was followed as Lienkamp et al. with minormodifications. (Lienkamp, et al. 2008 J Am. Chem. Soc. 130, 9836-9843.)Compound 1, 10 mol % DMAP and 1.9 equivalents of the 1,3-Di-Boc-2-ethylguanidine were dissolved in DCM. After all components dissolved, thesolution was cooled down to 0° C. in an ice bath, and 1 equivalent ofEDC was added. The solution was stirred over night. The reaction mixturewas diluted with DCM and washed with 10% KHSO₄ (3×25 mL) and sat. NaHCO₃solution (3×25 mL). Next, the organic phase was dried over Na₂SO₄ andfiltered. The volume of solution was reduced by vacuum evaporation, andthe product was run through a short alumina column. Vacuum evaporationof the solvent yielded the pure product 2. The yield ranged from ˜80%.

2

colorless solid. ¹H-NMR (300 MHz, CDCl₃): δ=11.50 (2H, s), 8.55 (2H, s),6.42 (2H, s), 5.3 (2H, d, J=6.0 Hz), 4.26 (4H, m), 3.71 (4H, m), 2.85(2H, s), 1.49 (18H, s), 1.48 (18H, s) ¹³C-NMR (75 MHz, CDCl₃): δ=171.3,163.4, 156.3, 153.1, 136.7, 83.2, 80.9, 63.6, 46.7, 39.4, 28.3, 28.2,HR-MS (FAB): calc. 754.37, found 755.3.

Synthesis of 3a

Compound 1 and 1.5 equivalents of the benzyl alcohol were dissolved inDCM, and the reaction mixture was stirred 3 days after the addition of10 mol % DMAP. The product 3a precipitated as a result of reaction inDCM, the precipitate was filtered and vacuum evaporation of residualsolvent yielded the pure product 3a. The yield ranged from ˜70%.

3a: Colorless Solid

¹H-NMR (300 MHz, DMSO-d6): δ=12.48 (1H, s), 7.41 (5H, s), 6.46 (2H, d,J=3.9 Hz), 5.11 (2H, m), 5.02 (2H, m), 2.78 (2H, d, J=2.7 Hz).

Synthesis of 3b

One equivalent of compound 3a, two equivalents of methanol and 10% DMAPwas dissolved in 1:1 mixture of DCM: THF. After all componentsdissolved, the solution was cooled down to 0° C. in an ice bath, and oneequivalent of EDC was added. The solution was stirred over night. Allthe solvent was evaporated and reaction mixture was dissolved in DCM,then washed with 10% KHSO₄ (3×25 mL) and sat. NaHCO₃ solution (3×25 mL).Next, the organic phase was dried over Na₂SO₄ and filtered. The volumeof solution was reduced by vacuum evaporation, and the product was runthrough a short alumina column. Vacuum evaporation of the solventyielded the pure product 3b. The yield ranged from ˜80%.

3b

colorless oil. ¹H-NMR (300 MHz, DMSO-d6): δ=7.35 (5H, m), 6.45 (2H, s),5.13 (2H, m), 5.06 (2H, m), 3.44 (3H, s), 2.84 (2H, m). ^(13c)-NMR (75MHz, DMSO-d6): δ=172.1, 171.6, 137.1, 137.0, 128.9, 80.3, 80.2, 66.4,51.9, 46.7. HR-MS (FAB): calc. 288.3, found 289.11.

3-Polymer Synthesis Synthesis of PTDM-1

The monomer 2 and G3-catalyst were dissolved in 1 mL DCM each andsubject to three freeze-thaw cycles. The monomer was added in one shotto the vigorously stirring catalyst solution at room temperature. After60 min, the living polymer chain was end-capped with an excess ofethylvinyl ether (1 mL, 754 mg, 10.5 mmol). The solution was allowed tostir 2 h. After evaporation of the solvent, the crude product wasdissolved in 1 mL THF and precipitated in pentane. The pentane solutionwas stirred for an additional 15 min and left standing unperturbed foran hour at 0° C. Then, the precipitate was collected by a fine sinterfunnel to yield product 4a. Polymer 4a were dissolved in 2 mL DCM and 2mL TFA for deprotection. After stirring overnight, the excess acid wasremoved by azeotropic distillation with methanol. After completeevaporation of the acid, samples were dissolved in water and dialyzedagainst RO water until the conductivity of water was ˜0.1 μS. Thendeprotected polymers were recovered by lyophilization. The finaldeprotected polymer 4b were protected from moisture and stored at 4° C.

4a

¹H NMR (300 MHz, CD₃CN): δ=11.54 (2H, br), 8.36 (2H, br), 7.33 (0.5H,br), 5.87 (trans) and 5.61 (cis) (2H total, br), 5.06 (cis) and 4.67(trans) (2H total, br), 4.18 (4H, br), 3.56 (4H, br), 3.15 (2H, br),1.48 (18H, s), 1.42 (18H, s).

4b

¹H NMR (300 MHz, CD₃OD): 7.34 (0.5H, br), 5.92 (trans) and 5.69 (cis)(2H total, br), 5.09 (cis) and 4.72 (trans) (2H total, br), 4.23 (4H,br), 3.48 (4H, br).

Synthesis of PTDM-2

The monomers 2, 3b and G3-catalyst were dissolved in 1 mL DCM each andsubjected to three freeze-thaw cycles. First, the monomer 3b was addedin one shot to the vigorously stirring catalyst solution at roomtemperature. After 5 min, the monomer 2 was added in the reactionmixture as a second block and reacted for 60 min. After 60 min, theliving polymer chain was end-capped with an excess of ethylvinyl ether(1 mL, 754 mg, 10.5 mmol). The solution was allowed to stir 2 h. Afterevaporation of the solvent, the crude product was dissolved in 1 mL THFand precipitated in pentane. The pentane solution was stirred for anadditional 15 min and left standing unperturbed for an hour at 0° C.Then, the precipitate was collected by a fine sinter funnel to yieldproduct 5a. Polymer 5a were dissolved in 2 mL DCM and 2 mL TFA fordeprotection. After stirring overnight, the excess acid was removed byazeotropic distillation with methanol. After complete evaporation of theacid, samples were dissolved in water and dialyzed against RO wateruntil the conductivity of water was ˜0.1 μS. Then deprotected polymerswere recovered by lyophilization. The final deprotected polymer 5b wereprotected from moisture and stored at 4° C.

5a

¹H NMR (300 MHz, CD₃CN): δ=11.53 (2H, br), 8.35 (2H, br), 7.34 (6H, br),5.86 (trans) and 5.60 (cis) (4H total, br), 5.07 (2H, br), 5.07 (cis)and 4.77 (trans) (4H total, br), 4.66 (2H, br), 4.17 (4H, br), 3.55 (4H,br), 3.48 (3H, br), 3.15 (4H, br), 1.46 (18H, s), 1.41 (18H, s).

5b

¹H NMR (300 MHz, CD₃CN): 6⁼7.09 (2H, br), 7.33 (6H, br), 7.01 (8H, br),5.85 (trans) and 5.62 (cis) (4H total, br), 5.04 (2H, br), 5.04 (cis)and 4.64 (trans) (4H total, br), 4.12 (4H, br), 3.46 (4H, br), 3.40 (3H,br), 3.20 (4H, br).

INCORPORATION BY REFERENCE

References and citations to other documents, such as patents, patentapplications, patent publications, journals, books, papers, webcontents, have been made in this disclosure. All such documents arehereby incorporated herein by reference in their entirety for allpurposes.

EQUIVALENTS

The representative examples are intended to help illustrate theinvention, and are not intended to, nor should they be construed to,limit the scope of the invention. Indeed, various modifications of theinvention and many further embodiments thereof, in addition to thoseshown and described herein, will become apparent to those skilled in theart from the full contents of this document, including the examples andthe references to the scientific and patent literature included herein.The examples contain important additional information, exemplificationand guidance that can be adapted to the practice of this invention inits various embodiments and equivalents thereof.

What is claimed is: 1-44. (canceled)
 45. A composition comprising: apolymer comprising the structural unit of Formula (IV):

wherein X₁ is O, CH₂ or substituted CH₂; Y₁ is a linking group; Z₁ is agroup that comprises —N(R_(z))₂ or

R_(z) is hydrogen, an alkyl, substituted alkyl, aryl, or substitutedaryl group; R is hydrogen, a C₁-C₁₂ alkyl group, or a poly(ethyleneoxide); and n is independently an integer from about 2 to about 300; anda therapeutic agent having a biological effect under physiologicalconditions.
 46. The composition of claim 45, wherein the therapeuticagent comprises a small molecule compound.
 47. The composition of claim45, wherein the therapeutic agent comprises a peptide.
 48. Thecomposition of claim 45, wherein the therapeutic agent comprises anantibody.
 49. The composition of claim 45, wherein the therapeutic agentcomprises a protein.
 50. The composition of claim 45, wherein thetherapeutic agent comprises a nucleic acid.
 51. The composition of claim45, wherein the polymer comprises the structural unit of the formula:

wherein X⁻ is an anion.
 52. The composition of claim 45, wherein Y₁comprising a —(CH₂)_(q)— group, wherein q is an integer from about 1 toabout
 6. 53. A composition comprising: a polymer comprising thestructural unit of Formula (IV):

wherein X₁ is O, CH₂ or substituted CH₂; Y₁ is a linking group; Z₁ is agroup that comprises —N(R_(z))₂ or

R_(z) is hydrogen, an alkyl, substituted alkyl, aryl, or substitutedaryl group; R is hydrogen, a C₁-C₁₂ alkyl group, or a poly(ethyleneoxide) group; and n is independently an integer from about 2 to about300; a diagnostic agent capable of emitting a detectable signal.
 54. Thecomposition of claim 53, wherein the diagnostic agent comprises afluorescent label.
 55. The composition of claim 53, wherein thediagnostic agent comprises a radioactive label.
 56. The composition ofclaim 53, wherein the diagnostic agent comprises a quantum dot label.57. The composition of claim 53, wherein the polymer comprises thestructural unit of the formula:

wherein X⁻ is an anion.